INDIAN J. CHEM., VOL. 20A, APRIL 1981

PUNCTIONALL Y substituted alkyltin halides.such as di-(4-ketopentyl)-tin halides and their

molecular complexes with 2,2' -bipyridyl(bipy) wereprepared by Poller et aU They studied the coordi-nation behaviour of the ester carbonyl group beforeand after complexation by PMR and found that apowerful donor like bipy rendered the carbonyl

'....groups free and proton resonance signals revertedto positions characteristic of uncomplexed ketopentylgroup. In this note we report the synthesis andcharacterisation of some ,B-carbomethoxy/butoxy-ethyl tin chloride complexes of mono- and bi-dentateligands.

Reactions were carried out under dry nitrogenblanket. Only analytical grade reagents and freshlydried and distilled solvents were used for the experi-ments. [3-Carbonyl alkoxyethyltin chlorides wereprepared as reported by Hutton et al.2'3.

Typical preparation of an addition compound isdescribed below.

[3-Carbomethoxyethyltintrichloride-l, 10-phenanthro-line addition compound ,B-Carbomethoxy-ethyltin trichloride (0.624 g; 0.002 mol) and 1,10-phenanthroline (0.360 g; 0.002 mol) were refluxedin benzene (50 ml). The pinkcoloured solid whichseparated was filtered, washed with benzene, and driedunder reduced pressure; yield·0.9 g (91 % of theory).

Other compounds listed in Table 1 were preparedsimilarly. The yields were above 90 % in all cases.

The Lewis acidity of ,B-carboalkoxyethyltin chlo-rides is certainly lower than the simple alkyl tin chlo-ride due to change in the hybridization of the bondingorbitals of tin (from Sp3 to spid and sp3d2). Both[3-substituted ethyltin trichloride and dichloride form1:2 and I:1 addition complexes with mono- andbidentate ligands. Most of these complexes arelight coloured solids soluble in benzene and insolublein hexane. Elemental analysis, molecular weight

J. inorg. nucl. Chem., 27 and conductivity measurements reveal that they aremonomeric covalent compounds; their mass spectra(by EI technique) could not be taken due to poorvolatility.

Bis-s-carbomethoxyethylrin dichloride, [3-carbo-methoxyethyltin trichloride and ,B-carbobutoxyethyltintrichloride exhibit in their IR spectra'] coordinatedcarbonyl frequency at 1667, 1645 and 1650 respec-tively. In their addition complexes with neutralmolecules, the vC=O shifts to higher frequency sideand is seen around 1725, which is the position fornon-coordinated C=O group.

Considerable changes are observed for the ligandvibrations in 2,2'-bipyridyl and 1,1O-phenanthrolinetin complexes particularly in the region 1400-1600(C=C and C=N ring stretching vibrations), 725-850(C-H out-of-plane deformation) and 400-450. In thefree 2,2'-bipyridyl molecule, the vC=C and vC=Nare observed at 1570 and 1420. New bands are ob-served at 1605, 1595 and 1460 as a result of complexformation. The out-of-plane C-H bending vibra-

did not observe any splitting of the NHz asymmetricdeformation and CHz rocking vibrations at 1595and915 cm" respectively.

The authors are indebted to UGC, New Delhifor financial support of this work.

References

1. BAILAR, r-.. J. C., Inorg Synth., 2 (1946), 222.2. BASOLO,F. &. PEARSON,R. G., Mechanisms of inorganic

reactions (Wiley Eastern, New Delhi), 1973.3. SYAMAL,A., J. scient. indo Res., 37 (1978), 661.4. BAILAR,Jr., J. C. & WORK, J. B., J. Am. chem. Soc., 68

(1946), 232.5. BLOCK, H. & GOLD, V., J. chem. Soc., (1959), 966.6. BASOLO,F., J. Am. chem. Soc., 72 (1950),4393.

7. BAILARJr., J.C.& WORK, J .B., J. Am. chem, Soc., 68(1946),232.

8. JONES, M. M., Elementary coordination chemistry (PrenticeHall, Englewood Cliff), 1964, 524.

9. LEVER,A. B. P., Inorganic electronic spectroscopy, (Elsevier,Amsterdam), 1968, 366.

10. MATSUOKA,N., HIDAKA, J. & SHIMURA,Y., Bull. chem.Soc. Japan, 39 (1966), ]257.

11. CELAP, M. B., MALINER, M. J. & JANJIC, T. J., Rev.Chim. ut«, 13 (1976), 269.

12. FAUST, J. P. & QUAGLIANO,J. v., J. Am. chem. ss«, 76(1954), 5346.

13. DUTTA, R. L. & SYAMAL,A., J. Indian chem, ss«, 45(1968), 138.

14. BJERRUM,J. & RASMUSSEN,S. E., Acta chem. scand., 6(1952), ]265.

15. NAKAMOTO,K. & MACCARTHY, P. J., Spectroscopy andstructure of metal chelate compounds (Wiley, New York),1968, 73.

16. FIGGIs, B. N., Introduction to ligand fields (Wiley Eastern,New Delhi) ]976, 248.

17. MORRIS, M. L. & BUSCH, D. H., J. Am. chem. ss«, 82(1960); ]523.

18. RIGG, J. M. & SHARWIN,E.,(1965), 653.

Molecular Addition Complexes of [3-Carbalkoxy-ethyItin Chlorides]

M. V. GARAD, Mrs. SARADAGOPINATHAN& C. GOPINATHAN*National Chemical Laboratory, Poona 411 008

Received 19 May 1980; revised and accepted 9 July 1980

~-Carbomethoxytehy 1-and ~-carbobutoxyethyl-tin trichloridesand bis-~-carbomethoxyethyltin dichloride form adducts withneutral Iigands such as pyridine, triphenylphosphine, hexamethyl-phosphoramide, triphenylphosphine oxide, trl-n-octylphosphlneoxide, 1,10-phenanthroline and 2,2'-bipyridyl, the last two actingas bidentate Iigands, The IR data indicate that the coordinationof the ester carbonyl to the tin is broken in these complexes andstill tin appears to be hexa-coordinated as evident from theJR, PMR and UV spectra.

tNCL Communication No. 2613.

412

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I

tIR Vmax in cm-1 and PMR chemical .shifts in 8 (ppm)throughout the paper.

\

rNOTES

TABLE 1 - CHARACTERISATIONDATA OF ADDITIONCOMPOUNDSOF ~-CARBALKOXYEIHYLTINCHLORIDES

No. Compound Cclour, m.p. Found co (Calc.)("C)

Sn Cl

1. ClaSn(es-Me).2 pyridine Colourless low melting 25.12(25.24) 22.60(22.62)2. ClaSn(es-Me).2 HMPA Colourless;!5 17.72(17.70) 15.87(15.86)3. ClaSn(es--Me).Ph3P Colourless, 64 20.60(20.68) 18.50(18.53)4. ChSn(es-Me). 2 OctaPO Yellow, low melting 11.02(10.95) 9.84(9.81)5. CI3Sn(es-Me).Bipy Pink, 198 25.30(25.35) 22.50(22.72)6. CIaSn(es-Me) .Phen Pink, 186 23.91(24.11) 21.57(21.61)7. CI3Sn(es-Me).2 Ph3PO Colourless low melting 13 .99(13.67) 12.22(12.25)8. CI3Sn(es-Bu).2 HMPA Colourless, 71 16.41(16.66) 15.02(14.93)9. .CI3Sn(es-Bu).Ph.P Pale yellow, low melting 19.01(19.27) 17.30(17.26)

10. CiaSn(es-Bu).2 Oct.PO Yellow low melting 10.39(10.54) 9.50(9.45)11. CI.Sn( es-Bu) .Bipy Pink, 163 23.28(23.26) 20.73(20.84)12. ClaSn(es-Bu).Phen Pink, 192 22.19(22.22) 19.88(19.90)13. CIaSn(es-Bu).2 Ph.PO Colourless, low melting 13.15(13.04) 11.74(11.69)14. CbSn(es-Me) a- 2 HMPA Colourless, 74 16.53(16.44) 9.82(9.82)15. Cl.Sn(es-Me)2' 20ct.PO Colourless low melting 10.48(10.45) 6.25(6.24)

." 16. Ci;Sn(es-Me)2.Bipy Pink 109 22.93(22.83) 13.59(13.64)17. CI.Sn( es-Me) a- Phen Colourless, 139 21.71(21.82) 13.10(13.04)

HMPA = Hexamethy1phosphoramideOCt3PO = Tri-a-octylphosphine oxide

tions of the ligand are seen at 750. This band issplitted and is seen at 720 and 770. All these indi-cate the bidentate nature of the ligand. Similarbehaviour is observed in 1,10-phenanthroline adducts(1) also.

In 1:2 adducts with triphenylphosphine oxide,the vP=O at 1190 in the free ligand is shifted to1160 and this lowering can be attributed to strongcomplex formation with tin. The carbonyl frequencyof the ester group reverts to the higher frequencyside. The vSn-C of [3-carboalkoxyethyltin tri-chloride at 578 is shifted to longer wave number(420) after complexation with bases like pyridine,2,2'-bipyridyl and 1,10-phenanthroline.

In organic solvents, 2,2' -bipyridyl appears'[to existin a trans-planar configuration with a small twistalong the central bond+. The presence of bands at

Ester

C~sn ~oCI N 0o

CI

TABLE 2 - UV DATA ON THE ADDITION COMPOUNDSOF~-CARBALKOXYTINTRICHLORIDESIN ACETONITRILE

"mal< (nm) Molar extinction coefficientSl No.*

56

11

245, 263,305,316 10,500, 5000, 12,800, 12,800227, 276 33.500, 31,500245, 263 8000, 4100, 8300, 8300306, 316232, 276238, 246, 283231, 265

121617

37,000, 26,5009400, 8430, 11,40046,000, 29,250

*SI. nos refer to compounds listed in Table 1.

/

(

238 and 283 nm is characteristic of the trans form.In 1:1 complexes, however, perfect planarity ismaintained and these bands exhibit a bathochromicshift to 245, 263, 305 and 316 nm. These newabsorption bands are associated with donor-acceptorcomplex formation even in acetonitrile solution. Inthe case of the 1,1O-phenanthroline (Amax at 230,265 nm) addition complexes also similar shift isobserved. However, the spectra of diestertin dichlo-ride complexes in acetonitrile are quite similar tothose of the above two ligands and it may be con-cluded that these complexes are dissociated in organicsolvents (Table 2).

The PMR data of ester tin chlorides and theirmolecular addition compounds in chloroform solu-tion are given in Table 3. [3-Carbobutoxyethyltintrichloride exhibits three triplets centred at 2.33,

TABLE3 - PMR CHEMICALSHIFTVALUESFOR ~-CARBALKOXY-ETHYLTINCHLORIDESAND SOMEOF THEIRADDITIONCOMPLEXES

IN CHLOROFORM

SI.No.*

Compound Chemical shift, 8ppm

-:CH.[tx] -CH2[~] -OCH.!-OCH.

2. CI3SnCH2CH2C02CH a- 2 HMPA3. Cl.SnCH2CH2C02CHa.PhaP7. CI3SnCH,CH2C02CH3.2Ph3PO8. CiaSnCH2CH2C02C.H •.2 HMPA9. C13SnCH2CH2C02C4H •.Ph3P

13. CI3SnCH2CH2C02C4H".2Ph3PO14. Ci.Sn[CH2CH.C02CH.]2.2 HMPA16. Cl.Sn[CH2CH2C02CH,j,.Bipy17 e , Cl.Sn[CH2CH2C02CH3h.Phen

(a) CI3SnCH,CH2C02CH.(b) Cl3SnCH2CH2CO,C,H9

(c) C12Sn[CH2CH~C02CH312

1.832.031.831.831.931.831.901.901.76

2.332.331.90

*Sl nos. refer to compounds listed in Table 1.

2.902.76

2.902.90

2.882.80

3.063.032.91

3.803.903.834.204.264.133.803.763.51

4.104.403.80

413

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INDIAN J. CHEM., VOL. 20A, APRIL 1981

3.03 and 4.40 attributable to ot-CHz, ,B-CHz and Dried and purified solvents were used. (P-C6HS

~OCH2 protons respectively; remaining protons C-6H4)2S'nCI:awas prepared as cited in literatures. Theof the butyl group resonate between 0.8 and 2.3. sodium salts of carboxylic acids were used. A typicalWhen ester tin trichlorides form.addition complexes, preparation of the desired complexes is given below :all the protons of the ester grouping resonate at Diacetato-bisip-biphenyls tin(/V) ~ A solution ofhigher magnetic field. This kind of shielding is ex- (p-C6H5-C6HJ:a-SnCI2(0.4957g, 1 mmol) in acetonepected for the protons of organotins, when strong .,...(30ml) was added to a solution of anhydrous sodiumdonor molecules interact with them thereby increas- . acetate (0.164 g, 2mmol) in methanol (30 ml) Theing the electron density around tin. Depending upon mixture was refluxed for 1 hr, filtered, the filtratethe basicity of the donor, the «-rnethylene protons concentrated (,.....10ml) under reduced pressure andare mostly shielded. Triphenylphosphine is a weak pet. ether (60-80°) added dropwise. A white preci-donor as seen from the small difference in chemical pitate formed was collected dried in vacuo andshifts. The possibility of metal to ligand d7;-p7; recrystallized from methylene chloride-pet. etherbonding can be ruled out as the observed differences (1 :1) to give a white crystalline solid in 80% yield.in chemical shift values of protons attached to (X- The isolated products are of good purity as indi-carbon atom is quite large. The stability of the cated by satisfactory elemental analyses (Table 1)adducts formed between diestertin dichloride and and PMR data. The complexes are white crystallinebases (in organic solvents) is poor. The resonance posi- solids and are fairly stable in dry and inert atmospheretions of the protons of the adducts show that in solu- but decompose in moist air. Conductances in puri-tion these complexes dissociate to a great extent. fied nitrobenzene (,......0.7ohm? em- mol") andSame conclusion can be drawn from UV spectral molecular weight determinations show that all thesedata also. complexes are essentially nonelectrolytes in nitro-

benzene and monomeric in benzene.Carboxylato ligand can bind to the metal atom

either as mono dentate, bidentate or in ionic form assuggested by Nakamoto? The separation valuebetween '12 ('1asOCO) and '11 ('Is OCO) was suggested<200 cm" for bidentate and> 200 em:" for mono-dentate carboxylato ligand10-13• IR spectra of com-plexes obtained presently indicate that for the com-plexes (1-6, Table 1), the separatio~ between '12(1 550±10 em:") and '11(1405 ± 5 cm") IS 140, 150, 150,145 130 and 140 cm? respectively, characterizingthe' bidentate mode of bonding for carboxylatoligand and giving thereby a coordination number ofsix to tin in these complexes. For complexes (7-9,Table 1), the separation value ('12-:'11) is 2~0, ~50and 265 cm" respectively, suggestmg contributionof monodentate mode of bonding for carboxylatoligand which possesses chlorine substituted methylgroup and thus a coordination number of four totin in these complexes .

References1. ABBAS,S. Z. & POLLER,R. C., J. chem, Soc. Dalton (1974),

1769.2. HUTTON,R.E.,OAKES, V.&BURLEY,J. W., Chern. Commun.,

(1976), 803.. 3. HUTTON, R. E. & BURLEY,J. W., J. organometal . Chem.,

156 (1978), 369.4. PAULINE,L. B., EUGENE,R. C., Jones, Y.C. & GARY,W. H.,

Inorg . Chem., 16 (1977), 462.

Preparation & Characterization of Some Bis(carboxy-lato )-bis(p-biphenyl)tin(IV) Complexes

ARJUN K. GARG, K. CHANDRA& M. C. JAINDepartment of Chemistry, S. D. College, Muzaffarnagar

and

N. KUMARt, B. S. GARG*. Department of Chemistry, University of Delhi, Delhi 110007

Received 16 June 1980; revised and accepted 5 August 1980

Bis( carboxylate ).bis(p-biphenyl)tin(IV) complexes of the type(p-C.Hs-C.H.)2Sn(02CR)2 (where R = -CH3, -C2Hs, n-C3H".n-C,H" n-CSHll' -C.Hs, -CH.CI, -CHCla or -CCI,)have been prepared and characterized by elemental analyses,molecular weight determinations, conductivity measurements,IR and PMR spectroscopy. The carboxylate ligand acts asmonodentate when R = -CH.CI, -CHCI2 and -CCla and asbidentate in the rest of the complexes.

ORGANOTIN carboxylates find industrial andbiological applications>", This prompted us

to prepare and characterise some new bistcarboxy-lato)-bis(p-biphenyJ)tin(IV) complexes of the type(P-CaH5-C6H4)2Sn(02CR)2 (where R = CHa, CZH5,

n-C3H5' n-C4H9, n-CsHU. C6H., CH2Cl, CHCl2 orccr,).

+National Physical Laboratory, Hillside Road, New Delhi110012

414

,(

TABLE 1 - CONDUCTIVITIESAND ELEMENTALANALYSESOF(p-C6Hs-C.H.)2Sn(02CR)2

m.p. Mol. wt Found(%) (Calc.)Complex CC) found

(R=) (calc.) C H Sn CI

1. -CH. 145 569 62.2 4.5 21.7(542.7) (61.9) (4.4) (21.9)

2. -C2HS 130 601 63.5 5.1 21.5(570.7) (63.1) (4.9) (20.8)

3. n-C,H7 230 637 64.4 5.7 20.2(598.7) (64.1) (5.3) (19.8)

4. n-C,Ht 170 653 65.7 5.6 19.4(626.7) (65.1) (5.7) (19.0)

5. n-CSHll 150 687 66.3 6.2 18.3(654.7) (66.0) (6.1) (18.1)

6. -C.H5 110 702 69.0 4.1 18.2(666.7) (68.4) (4.2) (17.8)

7. -CH2CI 175 634 55.2 3.8 20.1 11.3(611.7) (54.9) (3.6) (19.4) (11.6)

8. -CHCl2 155 711 49.3 3.0 17.8 20.7(680.7) (49.4) (2.9) (17.4) (20.85)

9. -CCI3 210 782 45.5 2.6 16.3 28.5(749.7) (44.8) (2.4) (15.8) (28.4)