COORDINATION CHEMISTRY OF ORGANOTIN (IV) COMPLEXES WITH NN DONOR LIGANDS

Cynthia Anak Paul Sebli

Bachelor of Science with Honours (Resource Chemistry)

2006

COORDINATION CHEMISTRY OF ORGANOTIN(IV) COMPLEXES WITH NN DONOR LIGANDS

CYNTHIA ANAK PAUL SEBLI

This project is submilted in part ia l fulfillment of the requirements for the degree of Bachelor of Science with Honows (Resource Chemistry)

Facult y of Resource Science and Technology UN IVERSITI MALAYSIA SARAWAK

2006

DECLARAnON

No portion o f the wo rk referred to this dissert at ion has been submitted in support o f an

application for another degree o f quali fication of this or any o thtr university of institu tion of

higher learning

Cynthia anak Paul Sebl i

Program of Reso urce Chemistry

Faculty of Resource Science and Techno logy

Uni versiti Malays ia Sarawak

ACKNOWLEDGEMENTS

I wo uld like to thank my supervisor Dr Md Abu Affan Resource Chemistry Program

UN IMAS for hi s constant guidance and continuous encouragement without which this work

would no t have been possible I also would like to express my appreciation to Mr Liew Yew

Zion MSc student of Resource Chemistry Program UN IMAS for his occasional help to

complete this report I would like to express my sincere thanks to all staffs of this chemistry

program for their inspiration and valuable ad vice Thank you very much to the Department of

Chemisrty Rajs hahi University Bangladesh for CHN analys is finally I would li ke to express

my grat it ude to my parents brother and sisters who were the constant so urce of inspiration

during the course of this project research work T hanks a lot to all my friends for encouraging

me co nstantly Last but no t least to those who involved d irectly or indirectly in giving hand to

me in completing this project and writing this report though you are unknown by name thank

you very much

Only GOD knows how to reward all of yo u Thank you

II

tgtasal Khldmlll Maklumat AkamIk ~tSrn 11 LHS SAIt~WAJ(

TABLE OF CONTENT Pages

LIST OF TABLES IV

LIST OF FIGURES V

ABSTRACT VI

10 Introduction 11 Coordination compounds of o rganolin(JV) ions 1 2 Objectives

20 Literature Review 2 21 Characterist ic ofN - do no r ligands 2 22 Bidentale nitrogen (NN-) donor ligands 3

23 Trid entate nitrogen (NNN -) donor ligands 5

24 Tetradentate nit rogen (NNNN-) donor ligands 5 25 Chelate Effect 6 26 Organot in(l V) complexes with NN donor ligands 7

30 Materials and Methods 13 3 I General Methods 13 32 Measurement 13 33 Synthes is ofligand (1) and it s orgallotin(JV) complexes (3-7) 14

33 1 Preparatio n of 2-acetylpyridillebenzo phenoneazine [C20 HI )N3] co ntaining NN-donor atoms (1 )

332 Synthesis of [Me2SnCh(C2o H I7NJ)] (3) 333 Synthesis of [Bu2S nClJ(C2HHI)N3)] (4) 33 4 Synthesis of (PhSnC I3(C2oHI )N3) ] (5) 335 Synthesis of(BuSnCI3(C1oH )N3)] (6) 336 Synthesis of[Bu3SnC I(C2oHI7NJ)] (7)

34 Synthes is o f ligand (2) and it s dio rganotin( lV) complexes (8-10) 341 Preparation of 2 -acetylpyridinep henylh yd razo ne [CI1 HI3

dono r atoms (2) 342 Synthesis of(Me2SnCI1(CuHuN3)] (8) 34 3 Synthes is of(Bu2SnCh(CIlHuN3)] (9) 344 Synthesis of [Ph2SnCh(C13 HIJN3)] (10)

40 Results and Discussion 4 1 Phys ical and ana lytica l data

14 15 15 15 15 16 17

3] containing 17 18 18 18

19 2 1

42 Spectroscopic studies of ligands (1-2) and their organotin(lV) corl1p lexes (3-10) 23 42 1 UV-Vis resu lts of ligand (1) and its organot in(lV) complexes (3-7) 23 42 2 IR spectral of liga nd ( 1) and its organotin(IV) complexes (3-7) 26 423 IR spectral 0 f ligand (2) and its organot in(fV) complexes (8-10) 3 I

50 Conclusion 38

60 Suggestion for Future Research 38

70 References 39

11

Pages LIST OF TABLES

Table I Elemental analys is fo r the ligands (1-2) and their organotin(l V) complexes (3-10) 21 Table 2 Mo lar conductance va lues fo r organotin(I V) complexes (3-10) 22 Table 3 The Am (nm) peaks of ligand (I ) and it s organotin(IV) complexes (3-7) 23 Table 4 Main IR data of the liga nd (1) and its o rgano tin(IV) complexes (3-7) (em) 28 Table 5 Ma in IR data of the liga nd (2) and it s dio rgano tin(lV) complexes (8-10) (em) 33

IV

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

COORDINATION CHEMISTRY OF ORGANOTIN(IV) COMPLEXES WITH NN DONOR LIGANDS

CYNTHIA ANAK PAUL SEBLI

This project is submilted in part ia l fulfillment of the requirements for the degree of Bachelor of Science with Honows (Resource Chemistry)

Facult y of Resource Science and Technology UN IVERSITI MALAYSIA SARAWAK

2006

DECLARAnON

No portion o f the wo rk referred to this dissert at ion has been submitted in support o f an

application for another degree o f quali fication of this or any o thtr university of institu tion of

higher learning

Cynthia anak Paul Sebl i

Program of Reso urce Chemistry

Faculty of Resource Science and Techno logy

Uni versiti Malays ia Sarawak

ACKNOWLEDGEMENTS

I wo uld like to thank my supervisor Dr Md Abu Affan Resource Chemistry Program

UN IMAS for hi s constant guidance and continuous encouragement without which this work

would no t have been possible I also would like to express my appreciation to Mr Liew Yew

Zion MSc student of Resource Chemistry Program UN IMAS for his occasional help to

complete this report I would like to express my sincere thanks to all staffs of this chemistry

program for their inspiration and valuable ad vice Thank you very much to the Department of

Chemisrty Rajs hahi University Bangladesh for CHN analys is finally I would li ke to express

my grat it ude to my parents brother and sisters who were the constant so urce of inspiration

during the course of this project research work T hanks a lot to all my friends for encouraging

me co nstantly Last but no t least to those who involved d irectly or indirectly in giving hand to

me in completing this project and writing this report though you are unknown by name thank

you very much

Only GOD knows how to reward all of yo u Thank you

II

tgtasal Khldmlll Maklumat AkamIk ~tSrn 11 LHS SAIt~WAJ(

TABLE OF CONTENT Pages

LIST OF TABLES IV

LIST OF FIGURES V

ABSTRACT VI

10 Introduction 11 Coordination compounds of o rganolin(JV) ions 1 2 Objectives

20 Literature Review 2 21 Characterist ic ofN - do no r ligands 2 22 Bidentale nitrogen (NN-) donor ligands 3

23 Trid entate nitrogen (NNN -) donor ligands 5

24 Tetradentate nit rogen (NNNN-) donor ligands 5 25 Chelate Effect 6 26 Organot in(l V) complexes with NN donor ligands 7

30 Materials and Methods 13 3 I General Methods 13 32 Measurement 13 33 Synthes is ofligand (1) and it s orgallotin(JV) complexes (3-7) 14

33 1 Preparatio n of 2-acetylpyridillebenzo phenoneazine [C20 HI )N3] co ntaining NN-donor atoms (1 )

332 Synthesis of [Me2SnCh(C2o H I7NJ)] (3) 333 Synthesis of [Bu2S nClJ(C2HHI)N3)] (4) 33 4 Synthesis of (PhSnC I3(C2oHI )N3) ] (5) 335 Synthesis of(BuSnCI3(C1oH )N3)] (6) 336 Synthesis of[Bu3SnC I(C2oHI7NJ)] (7)

34 Synthes is o f ligand (2) and it s dio rganotin( lV) complexes (8-10) 341 Preparation of 2 -acetylpyridinep henylh yd razo ne [CI1 HI3

dono r atoms (2) 342 Synthesis of(Me2SnCI1(CuHuN3)] (8) 34 3 Synthes is of(Bu2SnCh(CIlHuN3)] (9) 344 Synthesis of [Ph2SnCh(C13 HIJN3)] (10)

40 Results and Discussion 4 1 Phys ical and ana lytica l data

14 15 15 15 15 16 17

3] containing 17 18 18 18

19 2 1

42 Spectroscopic studies of ligands (1-2) and their organotin(lV) corl1p lexes (3-10) 23 42 1 UV-Vis resu lts of ligand (1) and its organot in(lV) complexes (3-7) 23 42 2 IR spectral of liga nd ( 1) and its organotin(IV) complexes (3-7) 26 423 IR spectral 0 f ligand (2) and its organot in(fV) complexes (8-10) 3 I

50 Conclusion 38

60 Suggestion for Future Research 38

70 References 39

11

Pages LIST OF TABLES

Table I Elemental analys is fo r the ligands (1-2) and their organotin(l V) complexes (3-10) 21 Table 2 Mo lar conductance va lues fo r organotin(I V) complexes (3-10) 22 Table 3 The Am (nm) peaks of ligand (I ) and it s organotin(IV) complexes (3-7) 23 Table 4 Main IR data of the liga nd (1) and its o rgano tin(IV) complexes (3-7) (em) 28 Table 5 Ma in IR data of the liga nd (2) and it s dio rgano tin(lV) complexes (8-10) (em) 33

IV

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

DECLARAnON

No portion o f the wo rk referred to this dissert at ion has been submitted in support o f an

application for another degree o f quali fication of this or any o thtr university of institu tion of

higher learning

Cynthia anak Paul Sebl i

Program of Reso urce Chemistry

Faculty of Resource Science and Techno logy

Uni versiti Malays ia Sarawak

ACKNOWLEDGEMENTS

I wo uld like to thank my supervisor Dr Md Abu Affan Resource Chemistry Program

UN IMAS for hi s constant guidance and continuous encouragement without which this work

would no t have been possible I also would like to express my appreciation to Mr Liew Yew

Zion MSc student of Resource Chemistry Program UN IMAS for his occasional help to

complete this report I would like to express my sincere thanks to all staffs of this chemistry

program for their inspiration and valuable ad vice Thank you very much to the Department of

Chemisrty Rajs hahi University Bangladesh for CHN analys is finally I would li ke to express

my grat it ude to my parents brother and sisters who were the constant so urce of inspiration

during the course of this project research work T hanks a lot to all my friends for encouraging

me co nstantly Last but no t least to those who involved d irectly or indirectly in giving hand to

me in completing this project and writing this report though you are unknown by name thank

you very much

Only GOD knows how to reward all of yo u Thank you

II

tgtasal Khldmlll Maklumat AkamIk ~tSrn 11 LHS SAIt~WAJ(

TABLE OF CONTENT Pages

LIST OF TABLES IV

LIST OF FIGURES V

ABSTRACT VI

10 Introduction 11 Coordination compounds of o rganolin(JV) ions 1 2 Objectives

20 Literature Review 2 21 Characterist ic ofN - do no r ligands 2 22 Bidentale nitrogen (NN-) donor ligands 3

23 Trid entate nitrogen (NNN -) donor ligands 5

24 Tetradentate nit rogen (NNNN-) donor ligands 5 25 Chelate Effect 6 26 Organot in(l V) complexes with NN donor ligands 7

30 Materials and Methods 13 3 I General Methods 13 32 Measurement 13 33 Synthes is ofligand (1) and it s orgallotin(JV) complexes (3-7) 14

33 1 Preparatio n of 2-acetylpyridillebenzo phenoneazine [C20 HI )N3] co ntaining NN-donor atoms (1 )

332 Synthesis of [Me2SnCh(C2o H I7NJ)] (3) 333 Synthesis of [Bu2S nClJ(C2HHI)N3)] (4) 33 4 Synthesis of (PhSnC I3(C2oHI )N3) ] (5) 335 Synthesis of(BuSnCI3(C1oH )N3)] (6) 336 Synthesis of[Bu3SnC I(C2oHI7NJ)] (7)

34 Synthes is o f ligand (2) and it s dio rganotin( lV) complexes (8-10) 341 Preparation of 2 -acetylpyridinep henylh yd razo ne [CI1 HI3

dono r atoms (2) 342 Synthesis of(Me2SnCI1(CuHuN3)] (8) 34 3 Synthes is of(Bu2SnCh(CIlHuN3)] (9) 344 Synthesis of [Ph2SnCh(C13 HIJN3)] (10)

40 Results and Discussion 4 1 Phys ical and ana lytica l data

14 15 15 15 15 16 17

3] containing 17 18 18 18

19 2 1

42 Spectroscopic studies of ligands (1-2) and their organotin(lV) corl1p lexes (3-10) 23 42 1 UV-Vis resu lts of ligand (1) and its organot in(lV) complexes (3-7) 23 42 2 IR spectral of liga nd ( 1) and its organotin(IV) complexes (3-7) 26 423 IR spectral 0 f ligand (2) and its organot in(fV) complexes (8-10) 3 I

50 Conclusion 38

60 Suggestion for Future Research 38

70 References 39

11

Pages LIST OF TABLES

Table I Elemental analys is fo r the ligands (1-2) and their organotin(l V) complexes (3-10) 21 Table 2 Mo lar conductance va lues fo r organotin(I V) complexes (3-10) 22 Table 3 The Am (nm) peaks of ligand (I ) and it s organotin(IV) complexes (3-7) 23 Table 4 Main IR data of the liga nd (1) and its o rgano tin(IV) complexes (3-7) (em) 28 Table 5 Ma in IR data of the liga nd (2) and it s dio rgano tin(lV) complexes (8-10) (em) 33

IV

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

ACKNOWLEDGEMENTS

I wo uld like to thank my supervisor Dr Md Abu Affan Resource Chemistry Program

UN IMAS for hi s constant guidance and continuous encouragement without which this work

would no t have been possible I also would like to express my appreciation to Mr Liew Yew

Zion MSc student of Resource Chemistry Program UN IMAS for his occasional help to

complete this report I would like to express my sincere thanks to all staffs of this chemistry

program for their inspiration and valuable ad vice Thank you very much to the Department of

Chemisrty Rajs hahi University Bangladesh for CHN analys is finally I would li ke to express

my grat it ude to my parents brother and sisters who were the constant so urce of inspiration

during the course of this project research work T hanks a lot to all my friends for encouraging

me co nstantly Last but no t least to those who involved d irectly or indirectly in giving hand to

me in completing this project and writing this report though you are unknown by name thank

you very much

Only GOD knows how to reward all of yo u Thank you

II

tgtasal Khldmlll Maklumat AkamIk ~tSrn 11 LHS SAIt~WAJ(

TABLE OF CONTENT Pages

LIST OF TABLES IV

LIST OF FIGURES V

ABSTRACT VI

10 Introduction 11 Coordination compounds of o rganolin(JV) ions 1 2 Objectives

20 Literature Review 2 21 Characterist ic ofN - do no r ligands 2 22 Bidentale nitrogen (NN-) donor ligands 3

23 Trid entate nitrogen (NNN -) donor ligands 5

24 Tetradentate nit rogen (NNNN-) donor ligands 5 25 Chelate Effect 6 26 Organot in(l V) complexes with NN donor ligands 7

30 Materials and Methods 13 3 I General Methods 13 32 Measurement 13 33 Synthes is ofligand (1) and it s orgallotin(JV) complexes (3-7) 14

33 1 Preparatio n of 2-acetylpyridillebenzo phenoneazine [C20 HI )N3] co ntaining NN-donor atoms (1 )

332 Synthesis of [Me2SnCh(C2o H I7NJ)] (3) 333 Synthesis of [Bu2S nClJ(C2HHI)N3)] (4) 33 4 Synthesis of (PhSnC I3(C2oHI )N3) ] (5) 335 Synthesis of(BuSnCI3(C1oH )N3)] (6) 336 Synthesis of[Bu3SnC I(C2oHI7NJ)] (7)

34 Synthes is o f ligand (2) and it s dio rganotin( lV) complexes (8-10) 341 Preparation of 2 -acetylpyridinep henylh yd razo ne [CI1 HI3

dono r atoms (2) 342 Synthesis of(Me2SnCI1(CuHuN3)] (8) 34 3 Synthes is of(Bu2SnCh(CIlHuN3)] (9) 344 Synthesis of [Ph2SnCh(C13 HIJN3)] (10)

40 Results and Discussion 4 1 Phys ical and ana lytica l data

14 15 15 15 15 16 17

3] containing 17 18 18 18

19 2 1

42 Spectroscopic studies of ligands (1-2) and their organotin(lV) corl1p lexes (3-10) 23 42 1 UV-Vis resu lts of ligand (1) and its organot in(lV) complexes (3-7) 23 42 2 IR spectral of liga nd ( 1) and its organotin(IV) complexes (3-7) 26 423 IR spectral 0 f ligand (2) and its organot in(fV) complexes (8-10) 3 I

50 Conclusion 38

60 Suggestion for Future Research 38

70 References 39

11

Pages LIST OF TABLES

Table I Elemental analys is fo r the ligands (1-2) and their organotin(l V) complexes (3-10) 21 Table 2 Mo lar conductance va lues fo r organotin(I V) complexes (3-10) 22 Table 3 The Am (nm) peaks of ligand (I ) and it s organotin(IV) complexes (3-7) 23 Table 4 Main IR data of the liga nd (1) and its o rgano tin(IV) complexes (3-7) (em) 28 Table 5 Ma in IR data of the liga nd (2) and it s dio rgano tin(lV) complexes (8-10) (em) 33

IV

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

tgtasal Khldmlll Maklumat AkamIk ~tSrn 11 LHS SAIt~WAJ(

TABLE OF CONTENT Pages

LIST OF TABLES IV

LIST OF FIGURES V

ABSTRACT VI

10 Introduction 11 Coordination compounds of o rganolin(JV) ions 1 2 Objectives

20 Literature Review 2 21 Characterist ic ofN - do no r ligands 2 22 Bidentale nitrogen (NN-) donor ligands 3

23 Trid entate nitrogen (NNN -) donor ligands 5

24 Tetradentate nit rogen (NNNN-) donor ligands 5 25 Chelate Effect 6 26 Organot in(l V) complexes with NN donor ligands 7

30 Materials and Methods 13 3 I General Methods 13 32 Measurement 13 33 Synthes is ofligand (1) and it s orgallotin(JV) complexes (3-7) 14

33 1 Preparatio n of 2-acetylpyridillebenzo phenoneazine [C20 HI )N3] co ntaining NN-donor atoms (1 )

332 Synthesis of [Me2SnCh(C2o H I7NJ)] (3) 333 Synthesis of [Bu2S nClJ(C2HHI)N3)] (4) 33 4 Synthesis of (PhSnC I3(C2oHI )N3) ] (5) 335 Synthesis of(BuSnCI3(C1oH )N3)] (6) 336 Synthesis of[Bu3SnC I(C2oHI7NJ)] (7)

34 Synthes is o f ligand (2) and it s dio rganotin( lV) complexes (8-10) 341 Preparation of 2 -acetylpyridinep henylh yd razo ne [CI1 HI3

dono r atoms (2) 342 Synthesis of(Me2SnCI1(CuHuN3)] (8) 34 3 Synthes is of(Bu2SnCh(CIlHuN3)] (9) 344 Synthesis of [Ph2SnCh(C13 HIJN3)] (10)

40 Results and Discussion 4 1 Phys ical and ana lytica l data

14 15 15 15 15 16 17

3] containing 17 18 18 18

19 2 1

42 Spectroscopic studies of ligands (1-2) and their organotin(lV) corl1p lexes (3-10) 23 42 1 UV-Vis resu lts of ligand (1) and its organot in(lV) complexes (3-7) 23 42 2 IR spectral of liga nd ( 1) and its organotin(IV) complexes (3-7) 26 423 IR spectral 0 f ligand (2) and its organot in(fV) complexes (8-10) 3 I

50 Conclusion 38

60 Suggestion for Future Research 38

70 References 39

11

Pages LIST OF TABLES

Table I Elemental analys is fo r the ligands (1-2) and their organotin(l V) complexes (3-10) 21 Table 2 Mo lar conductance va lues fo r organotin(I V) complexes (3-10) 22 Table 3 The Am (nm) peaks of ligand (I ) and it s organotin(IV) complexes (3-7) 23 Table 4 Main IR data of the liga nd (1) and its o rgano tin(IV) complexes (3-7) (em) 28 Table 5 Ma in IR data of the liga nd (2) and it s dio rgano tin(lV) complexes (8-10) (em) 33

IV

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Pages LIST OF TABLES

Table I Elemental analys is fo r the ligands (1-2) and their organotin(l V) complexes (3-10) 21 Table 2 Mo lar conductance va lues fo r organotin(I V) complexes (3-10) 22 Table 3 The Am (nm) peaks of ligand (I ) and it s organotin(IV) complexes (3-7) 23 Table 4 Main IR data of the liga nd (1) and its o rgano tin(IV) complexes (3-7) (em) 28 Table 5 Ma in IR data of the liga nd (2) and it s dio rgano tin(lV) complexes (8-10) (em) 33

IV

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

LJST OF FIGURES Pages

Figure I Examples of nitrogen donors with tertiary Sp2-hybridized N atoms 2 Figure 2 22 -bipyrimidine 3 figure 3 23-bis(2-pyridyl)pyrazine 3 Figure 4 [(2-pyridyl-methylene)( phenyl)hydrazinc) 4 Figure 5 66- bis(pirazoloyl)-2 2bipyridin e 4 Figure 6 Pentamethyld iethylenetriamine 5 Figure 7 Nitrophenylethylenediaminediacetic acid 5 Figure 8 Pyridine-2-carbaldehyde azine 6 Figure 9 12 -di(pyridine-2-aldiminoketimino) 6 figure 10 Structure of (a) nicke l hexaamine (b) nickel triethylenediamine and their stability 7 Figure II Dimethyltin(IV) and mono-N-butyltin(lV) trichloride with severa l N- substituted

pyridine-2-carbaldimine 7 Figure 12 SnR2CI2-35-dimethyl-1 -(2 -pyrid yl)pyrazole 8 Figurc 13 Proposed st ructures ofdi-n-butyltin(lV) complexes with pyruvoylamino acid oximes 89 figure 14 Proposed structure of BU2Sn(lV)-2-hydroxyimino-3-phenyl-propionic acid complex 9 Figure IS Proposed (a) MejSn(6-thiopurine) (b) nBu2Sn(6-thio purine)2 and (c) Ph)Sn(6shy

thiopurine) 10 Figure 16 I -methylimidazo le donor I 1 Figure 17 Proposed structures tor organo tin(lV) derivatives of I-dimethylimidazole II Figure 18 [Bis(35-d imethyl-4-( 4 -pyridyl)pyrazole) diphenylt in dichloride 12 Figure 19 UV-vis spectra of li gand ( I) and it s phenyltin(lV) complex (5) 24 Figure 20 UV-vis spectra of ligand ( I ) and it s butyltin(lV) complex (6) 25 Figure21 IRspectrum for ligand [C20 HI 7NJ) ( I) 29 Figure 22 JR spectrum of dimethyltin(lV) complex [(CH3 12S nCh(C~HI7N ) ) ] (3) 30 Figure 23 IR spectrum fo r ligand (CI]H I] )) (2) 34 Figure 24 IR s pectrum of dimet hy ltin(IV) complex [(CH))2SnCI2(CI]H1 ) ))] (8) 35 Figure 25 Proposed structure of the diorgano tin(IV) complexes (3-4) of the ligand (I) 36 Figure 26 Proposed structure of the monoorgano tin(lV) complexes (5-6) of the ligand (1) 36 Figure 27 Proposed structure of the triorganot in(IV) complexes (7) of the Iiganct ( I) 37 Figure 28 Proposed structure of the dio rgano tin(lV) complexes (8-10) of the ligand (2) 37

v

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Coordination Chemistry of Organotin(lV) complexes with NN Donor Ligands

Cynthia anak Paul Sebti

Resource Chemistry Facu lty of Resource Science and Tethnology

Universl ti MalaysIa Sarawak

ABSTRACT

Two ligands have been formed by condensation reaction of 2-acetylpyrid ine with benzophenonehydrazone and phenylhydrazine in 11 molar ratio Organotin(lV) complexes of2shyacetylpyridinebenzophenoneazine and 2-acetylpyrid inephen ylh ydrazo ne have been synthes ized where the ligands are acted as bidentate NN chelating agent The characterization of the ligands (1-2) and their organotin(lV) complexes has been made on the basis of elemental analyses molar conductances UV-vis ible and FTlR spectral studies On the basis of analytical and spectral data octahedral (coordination number six) structures have been proposed

Key words 2-acetylpyrid inebenzophenoneazine 2-acety1pyr id i nep heny Ihydrazo nc o rganotin(lV) complexes spectral studies

ABSTRAK

Dua jenis ligan lelah dihasilkan melalui tindakbalas kondensasi eli onlam 2-aselilpiridina dengan benzoenonhidrazon dan enilhidrazina Kompleks organolin(IV) felah disil1lesis melalui beberapa siri tindakbalas dengan 2-asetilpiridinabenzoenonhidrazon dan 2shyaselilpiridinaenilhidrazina yang berlidak sebagai ligan NN bidenlal Pencirian lerhadap kompleks (3-10) dan ligan (1-2) lelah diakukan dengan menggunakan beberapa kaedah iaitu analisis elemen molar kondukliviti kajian spektra bagi UV-v is dan FTfR Berdasarkan kajian ke alas data analilikal dan spektra maka slnlktur oklahedral (enam nombor koordinasi) lelah dicadangkan

Kala kunci- 2-aseti Ipiridinabenzoen(nazina 2 -asel ilp iridinae n ilh idrazon kompleks organolill(IV) kajian speklra

V I

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

10 Introduction

11 Coordination compounds of organotin(IV) ions

O rganotin(l V) complexes are highly interested areas especiall y for their structural and

biological activities (Mahmood el al 2004) Organotin(lV) complexes with the ligands

containing 0 0- 0 N- and 0 S- donor atoms have investigated by many researchers

Organotin(lV) complexes have been demonstrated to ex hib it relatively hig h ant itumo r activity

as emphasized in recent surveys (Xanthopoulou el al 2003) For complexes [SnR1X2(LL) ]

where LL is an N N- a bidentate nitrogen donor ligand antitumor activity depends on the Sn-N

distances (gt239 A and lt239 A) for the active and inact ive compounds (Alvarez-Boo e ai

2003 Xanthopou lou el ai 2003 Chojnacki el ai 2001) respectively which suggests that

dissoc iat ion of the ligand is a s ignificant step in their mechanism Due to such a wide range of

app lications new o rganot in(IV) with different types of NN- donor ligands are of particular

interest The present project research has reported the preparation and characterization of several

organotin( I V) complexes with the NN- donor ligands namely 2shy

acetylpyr idinebenzophenoneazine ligand (1) and 2-acetylpyridinepheny lhydrazo ne ligand (2)

12 Objectives

The objectives of this study are

I To synthes ize NN- donor ligands

II To synthesize organotin(lV) complexes with NN- donor ligand s

III To characterize NN - donor liga nds and their organotin(fV) complexes using molar

conductances CHN analyses liV-visible and FT-I R spectral studies

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

20 Literature Review

21 Characteristic ofN- donor ligands

N it rogen dono r ligands have great in fl uence upo n coord ination chemis try e nvironment

Nit rogen do nor ligands are class ified into 3 gro ups that are Sp3 Sp2 and sp T his class ifi cation is

based on hybridization ofN atom

The example of Spl -hybrid ized nitrogen do no r atoms is trimethy lamine N-H bonds are

always unsuitable fo r organo metallic reactio n The H atom presence make the environment

become ac idic

Any ligands that contain sp2-hyb ridized nitrogen atoms especially N atom is a part of

aro matic system has big potentia l coo rdination chemistry This kind o f ligands is mo re

fu nctional coo rdinat io n chemistry if they are bidentate or tetradent ate

T hese are so me example o f the nitrogen do nor ligands that has been synthesized by

prev io us researchers

~-~NII~ ~Jo ~

N

~

N

N ~

Figure 1 Examples ofnit rogcn donors with tertiary sp2-hyb ridized N atoms

shyN

2

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

The presence of C=N and C= C double bond s in several mol ecu les in Figure I can make

them easily to experience furt her reaction such as nucleophilic attack and hydrogenation The

organic nitrogen dono r with sp hybridizat io n is nitriles group T his group acts as lab ile ligand s

which mean they could be rep laced by appropriate reagents Nitril es are qu ite lab ile towards

nucleophilic attack once coordinated

22 Bidentate nitrogen (NN-) donor ligands

NN- donor ligand is a co mpound has two N atoms that are able to bond with any central

metal cation Some common examp les of this kind of ligand are ethy lened iamine(en) and

dipyridine

Shava leev el ai (2002) have reported the synthesis o f bidentate 22-b ipyr imidine a nd 2

3-bis(2-pyrid yl) as new NN- donor ligand (Figure 2-3) Both of ligands act as bidentate nitrogen

donor ligand via externa l vacant NN - donor diimine type binding sit es

Figure 2 22 -b ipyrim id ine

_NN_

Figure 3 23-bis(2-pyrid yl)pyraz ine

3

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Another example o f NN - dono r ligand [(2 -pyrid yl-methylene)(phenyl)hydrazineJ

reported by Tarafder el al (2003) The structure of [(2-pyridyl-meth ylene)(phenyl)hyd razineJ is

shown in Figure 4 This ligand [(2-pyridyl- methylene)(phenyl)hydrazineJ also acted as bidentate

NN - nit rogen donor ligand and iso lated ITo m the condensation o f pyridin e-2-ca rboxaldehyde

with phenylhydrazine in ethano l

Figure 4 [(2-pyrid yl-methylene)( phenyl)hydrazineJ

Recentl y 66 -bis(pirazo lyl)-22 bipyridine o ne type o f NN - dono r liga nd which is

obtained by Kowalczyk and Skarzewski (2005) which acts as chiral NN bide ntate donor ligands

Mo lecular structure is sho wn in Figure 5

Me ~Me MeO~ ~

Ph N_NT(Ny

C CI NiCI2(Ph3P)2 Ph3P Zn

DMF

(a)

(b)

(a) 2-ehloro-6-[3-( l-methoxy-l-phenyl- eth yl)-5-methylpyrazo l-l-yIJpyr id ine (b) 66 -bis(pirazo ly l)-22 -bipyridine

Figure 5 66- bis(pirazo lyl) -22 bipyridine

4

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Kbillmal MakJumal Ak~mik 1T(Vf5-1 t v ~ v WAK

23 T ridentate nitrogen (NNN-) donor ligands

One of the most commo n tridentate nitrogen donor ligand IS

pen ta methyld iethy lenetria m in e has been reported by Patel el al (2004)

Pentamethyldiethylenetriamine is a tridentate nitrogen donor ligand with donor groups suitably

placed for forming two 5-membered chelate ring Pentamethyldiethylenetriamine also acts as

superoxide scavenging ability The donor ligand mo lecular structure can be seen in Figure 6

Figure 6 Pentamethyldiethylenetriamine

Another type of tridentate nitrogen donor ligand (NNN-) IS

nitrophenylethylenediaminediacetic acid (Figure 7) has been reported by Allah er at (2004)

Nitrophenylet hylenediaminediacet ic ac id acts as tridentate ligands (via the two ac ids and the

tertiary amine function s)

Figure 7 N it rophenylethylenediamined iacet ic acid

24 Tetradentate nitrogen (NNNN-) donor ligands

One ofthe NNNN- donor ligand having a pyridyJ back bone is synthes ized by Toupance

el ([I (2002) It is pyridine-2-carbaldehyde azine that is shown in Figure 8 Pyridine-2shy

carbaldehyde azine act as tetradentate nitrogen dono r ligand v ia its nitrogen atom

5

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Figure 8 Pyridine-2-carbaldehyde azine

Kulshreshtha and his co workers (1989) reported the synthesis of new tetradentate

nitrogen donor ligands 12-di(pyridine-2-aldiminoketimino) They were derived from the

condensation reaction of pyridine 2-carboxyaldehyde or 2-acetylpyridine with ethylenediamine

and propylenediamine and refluxing condition in ethanol The ligand structure is shown in

Figure 9

R R

+ NH (CHC H )nNH bull -N-(CH 2)n-N + 2 H2o( o-L) N

N ~ =----shy

Figure 9 12 -di(pyridine-2-aldiminoketimino) where R= HCH) n = 23

25 Chelate Effect

Chelate means any ligand that has capability bo nded with any central metal atom through

more than one donor ato m This chelate effect can be seen c learly by comparing the multidentate

ligand complexes and mo nodentate ligand co mplexes In fact the multidentate ligand complexes

are more stab le compare to monodentate ligand complexes From the example

has chelate effect since the the ligand coordinated via more than one nitrogen atom of the ligand

Whereas [Ni(NH))6l 2 + form the complex with monodentate nitrogen atom See the example as

tollow

6

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

2+

2 6I I - (q) + log B= 86

(a) Nickel hexaamine

2+

Ni ~ f- 3H1NCH1CH1NH2(aq)

log B= 18 3

(b) Nickel triethylenediamine

stability

26 Organotin(V) complexes with NNINNN donor ligands

Tanaka el of (1979) ha ve synthes ized 11 mo lecular add ucts of dimethyltin(IV) and

mono -N-butyltin(lV) trichloride with seve ral N- substituted pyridine-2-carbaldimine (Figure

1 I )

n=1 R=n-butyl n=2 R=Me R= Me 4-MeC6 H 4

Figure II Dimethyltin(IV) and mono-N -butyltin(lV) trichlo ride with several N- substituted pyridine-2-carbaldimine

7

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

When the substituent R on the imine nit rogen atom is Me Et or CH1Ph the adduct exist

as a mixture of two iso mers in aceton itrile on the basis of I H chemica l shifts of the ligand

protons and their spin-spin coupling constants wit h the tin nuclei

Alvarez-Boo and hi s co-workers (2003) have synthes ized SnR1CI1-3 5-dimethyl-l-(2shy

pyridyl)pyrazo Ie

R=Me n Bu Ph etc

Figure 12 SnR1Cb-35-dimethyl-I-(2 -pyridy l)pyrazo le

Szorcsik and his co-workers (2003) have synthesized I 1 mo lecular adducts of

pyruvoylamino acid oximes with 8u)SnO that is shown in Figure 13

(a)

8

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

H~ CH3

BU I N= C

tC

in-N =0

Bu I o CH-R

~C II o

(b)

Figure 13 Proposed structures of di-n-butyltin(lV) complexes with pyruvoylamino acid oximes

The organotin(IV) moieties react with the carboxylate [OJ and peptide and oxime [N]

ato ms of the ligands is clearly seen by using FT-IR and Raman spect ra (Szorcsik el al 2003)

Found that in the most cases the -COO- group monodentately coord inated to the central atom

and most of the complexes probably have monomeric structures (Szorcsik et at 2003)

Figure 14 Proposed structure of BuS n(V)-2-hydro xy imino-3-p he nyl- prop ionic acid complex

Zhang and his co workers (2004) have synthesized triphenyl(6-thiopurin yl)tin and

in vestigated the structure using X-ray diffi-action

9

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

(a)

s

t~)N N

Ph~1 Sn-Ph

Ph I N N

ltNJ S

(e)

Figure 15 Proposed (a) Me3Sn(6-thiopurine) (b) nBu2S n(6-thiopurineh and (e) Ph3Sn(6-thiopurine)

10

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Organotin(IV) complexes containing mono or bidentate N- donor ligands as 1shy

methylimidazo le derivatives have been reported by Pettinari el of ( 1998)

HC-N II

HC CH N I CH3

Figure 16 I-methylimidawle donor

R=Me Et Bun or Ph n=1 2 3

(a)

Z= X or R R= Me Et Bun Ph n= 1 2 3 X= CI Br I

(b)

Figure 17 Proposed structures for organotin(IV) derivatives o f 1shydimeth ylimidazole

11

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Recently Cui and his co-workers (2005) have been studied the donating ability of ligand

35-dimethyl-4-(4-pyridyl)pyrazole with organotin(lV) chloride(s) They found that nitrogen

atom ofpyridyl exhibits stronger donating ability compare to nitrogen atom in the pyrazole ring

toward tin atom The [bis(3S-dimethyl-4-(4-pyridyl)pyrazole] diphenyltin dichloride structure

is shown in Figure 18

~

~ CI IQN---- - NH

N-Sn--N H~ II ---=Nilt l I

Figure 18 [Bis(3 S-dimethyl-4-( 4 -pyridyl)pyrazole] diphenyltin dichloride

From the literature reviews studies on organotin(lV) complexes of corresponding NN-

donor ligands are less studied (Alvarez-Boo el aI 2003 Matsubayashi el aI 1971) Therefore

the author has undertaken this project for the purpose of synthesizing and characterizing

organotin(IV) complexes with NN- donor ligands

12

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

30 Materials and M~thods

31 General Methods

All chemicals were obtained from Fluka Aldrich and JT Baker All solvents were

distilled base on the published methods by Armarego before used (Almarego and Perrin 1996)

All solvents were distilled and dried before used as follows methanolethano l purified and dried

from distillation with magnes ium turning and iodine and dry benzenehexane is obtained by

distilling w ith sod ium and sma ll amo unt of benzophenone and purified und er nitrogen from

sodium benzophenone ketyl

All the purifi ed and dried so lvents were kept in molecular sieves All the reactions were

conducted under dry nitrogen atmosp here using Schlenk Vacuum Line techniques

32 Measurement

Bidentate nitrogen donor ligands and their organotin(IV) complexes were characterized by

elemental and spectra l anal yses E lemental analyses are CHN analyses and mo lar condu ctance

analyses The spectral studies are UV-vis ible and FTIR spectra studies Organotin(lV) halide(s)

complexes were preserved in freezer for long-term storage and stability

The IR spectra were recorded as KEr disc using Perkin Elmer Spectrum OX Fouriershy

Transform Spectrometer (4000-400 ern) at UNIMAS Electronic spectra werc recorded with

benzene as a solvent on a Perkin Elmer Lambda 2S UV-Visible spectrometer at UNIMAS The

concentration is I xlO-4 M Molar conductances were measured at room temperature using Hanna

EC 215 Conductivity Meter at UNlMAS and using methanol as so lvent

13

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

33 Synthesis of ligand (1) and its organotin(lV) complexes (3-7)

331 Preparation of 2-acetylpyridinebenzophenoneazine ICzoHI7N3] containing NN- donor

atoms (1)

A solution of 2-acetylpyridine (0486 g 0004 mole) in an absolute ethanol (20 rnL) was

added to a solution of benzophenonehydrazone (0784 g 0004 mole) in absolute ethanol (20

mL) The mixture was heated to reflux for 4-5 hours under nitrogen atmosphere with stirring

The color of the solution was changed from pale yellow to yellow The mixture was let in the

refrigerator for overnight and the required product precipitated out as white micro crystals The

yellow solid was filtered off and washed with pentane The residue was recrystallized from

pentane Yield 0560 g 4409 mp 108-110 0c

Schematically the reaction between 2-acetylpyridine and benzophenonehydrazone to form

2-acetylpyridinebenzophenoneazine and water produced during condensation reaction as by-

product showed as below

~CH H N2 absolute ethanol N

N-N_ H O+ bull N + 2OyCH H IStirredrefluxed for 5-6 hours o --- ~

I 1 ~-

(a) (b) (c)

Where a 2-acetylpyridine b benzophenonehydrazonc c 2shyacetylpyridinebenzophenoneazine

14

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

Synthesis of organotin(lV) complexes with NN- donor ligand (1)

332 Synthesis of IMelSnCIl(CloHI7NJ)] (3)

Ligand (1) (0299 g 0001 mole) was suspended in hexane (20 mL) and warmed s lowly to

give a palc ydlow so lution This was then slowly added to a suspens ion ofMe2SnCb (0219 g

0001 mole) in hexane (20 mL) with constant stirring under nitrogen atmosphere The color of

the mixture was changed from pale yellow to yellow The solution mixture was refluxed for 3-4

hours aft er which a whit e precipitation was obtained The mi xture was allowed to coo l and

filtered off The white precipitate was washed with hexane and dried in vacuum des icato r Yield

03 89 g 7509 mp 135- 138 dc

333 Synthesis of [BulSnClz(CzoHI7NJ)] (4)

This dibutyltin(IV) comp lex (4) was prepared by applying similar method as described tor

synthes izing complex (3) by replacing Me2SnCb with BU2SnCb (0310 g 0001 mole) The

white precipitate was washed with hexane and dried in vacuo over sili ca ge l Yield 0389 g

7754 mp 120-122 DC

334 Synthesis of ]PhSnCb(C20H 17NJ)] (5)

This phenyltin(IV) complex (5) was prepared by applying the same methods as for

synthes izing complex (3) by replac ing Me2SnCI2 with PhSnCb (0300 g 0001 mole) The white

precipitate was was hed with hexane and dried in vac uo over silica gel Yie ld 0585 K 9750

mp 162-165 DC

335 Synthesis of [BuSnCi3(CzoH 17NJ)] (6)

This butyltin(lV) complex (6) was prepared by using similar procedures as described for

synthesizing complex (3) by replacing Me2SnCb with BuSnCI) (0281 g 000 1 mole) The white

15

precipitate was washed with hexane and dried in vacuo over silica gel Yield 0554 g 9551

mp 138-141 dc

336 Synthesis of [BuJ SnCl(CzoH 17 N))1 (7)

This tributyitin(lV) complex (7) was prepared by using similar method as a applied for

synthesizing compl ex (3) by replacing MelSnCh with Bu)SnCI (0325 g 000 ] mole) The white

precipitate was washed w ith hexane and dried in vacuo over s ili ca geL Yield 0552g 8850

mp91-94 degC

16