3ftfbsdi sujdmf 4zouiftjt 4qfdusptdpqz …downloads.hindawi.com/archive/2013/426712.pdfpg (&. /...

Hindawi Publishing CorporationISRN Inorganic ChemistryVolume 2013 Article ID 426712 7 pageshttpdxdoiorg1011552013426712

Research ArticleSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexeswith 2-Amino-5-bromopyridine as Ligand

Raziyeh Arab Ahmadi1 Farshideh Hasanvand1 Giuseppe Bruno2

Hadi Amiri Rudbari3 and Saeid Amani1

1 Chemistry Department Faculty of Sciences Arak University Dr Beheshti Avenue Arak 38156-8-8349 Iran2Dipartimento di Chimica Inorganica Universita di Messina Vill S Agata Salita Sperone 31 98166 Messina Italy3Department of Chemistry University of Isfahan Isfahan 81746-73441 Iran

Correspondence should be addressed to Saeid Amani s-amaniarakuacir

Received 6 November 2012 Accepted 9 December 2012

Academic Editors K Y Choi A Karadag A Lehtonen and X-B Wang

Copyright copy 2013 Raziyeh Arab Ahmadi et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

e synthesis spectroscopic and magnetic characterization of two new copper(II) and cobalt(II) complexes are described Bothtwo compounds have the general formula [M(L)2(Cl)2] in which L = 2-amino-5-bromopyridine ese complexes were preparedin one-step synthesis and characterized by elemental analysis FTIR UV-Vis and EPR spectroscopy Moreover the single crystalstructure of complex (1) was studied by the X-ray diffraction method is compound consists of mononuclear units consistingof two ligands linked to metal via the nitrogen of pyridine ring e UV-Vis spectra of copper(II) and cobalt(II) complexes showthree and ve absorption bands respectively attributed to the d-d transition of the metal ion ligand rarr metal charge transferand 120587120587 rarr 120587120587lowast or 119899119899 rarr 120587120587lowast transitions of the ligand e FTIR spectra show MN2Cl2 vibrations at 500ndash300 cmminus1 e complexesshow room temperature magnetic moments of 178 BM and 412 BM for Cu(II) and Co(II) respectively e X-band electron spinresonance (ESR) spectra of Cu(II) complex in DMF or DMSO frozen at liquid nitrogen temperature show the typical Δ119872119872S = plusmn1transition

1 Introduction

e study of transition metal ion complexes by magneticand optical techniques has furnished a considerable bodyof empirical data much of which can be understood interms of the phenomenological ligand eld theory [1] emajor portion of this data is primarily concerned withcomplexes containing a single paramagnetic transition metalion relatively little information is available on dimeric andtrimeric coordination complexes [2] Since copper(II) ionsare widely distributed in biological systems a signicantamount of research has centered on the search for relativelysimple copper(II) complexes which may display some ofthe properties of the metalloproteins One such system ofpotential importance is that formed by copper(II) halides

with pyridine and substituted pyridines [3] Small low-molecular-weight copper(II) coordination complexes withN-donor ligands have frequently been used to model theactive site in copper proteins with the aim of obtaininginsight into the correlation between structure and the spec-troscopic andmagnetic behavior [4ndash7] Cobalt(II) complexesare important in biology mainly because of coenzyme B12[8] A report of insulin-like action of cobalt(II) chlorideimplies that such metal complexes may have similaritieswith vanadium compounds which exhibit insulin-like effects[9ndash16] Electronic properties of cobalt(II) compounds havereceived substantial attention [17ndash19] in part due to thefact that many of these complexes bind oxygen reversibly[20] and are model systems for vitamin B12r Cobalt is anecessary trace element in mammals and has many uses in

2 ISRN Inorganic Chemistry

NH2N

Br

S 1 Structure of ligand

medicine magnetic resonance imaging and drug delivery[21] Cobalt ethylenediamine complexes are potent antimi-crobial agents [22] Low-spin cobalt porphyrins [23 24] are ofinterest since cobalt-substituted hemoglobin ldquocoboglobinrdquobinds oxygen in a cooperative fashion [25] e growth ofcobalt chemistry has necessitated the development of modelsto account for and predict the spectroscopic properties ofcobalt(II) complexes Cobalt(II) compounds have interestingmagnetochemistry as shown in a recent review on magneticmetal-organic frameworks [26] Strong magnetic anisotropyof high-spin cobalt(II) is at the origin of the increasinginterest in polynuclear compounds containing this metal ion[27] Several examples of high-nuclear complexes with six-coordinate cobalt(II) behaving as single molecule magnetsand single chain magnets have been reported [28ndash31] Wehave been interested in copper(II) and cobalt(II) complexeswith 2-amino-5-bromopyridine as ligand Such complexeshave potential for antibacterial activities andwewill focus onthis subject in the future e complexes were synthesized ina one-step synthesis and characterized by elemental analysisFourier transform infrared (FTIR) electronic spectra roomtemperature magnetic moments and a crystal structure

2 Experimental

21 Chemicals All of the chemicals and solvents were pur-chased fromMerck Chemical Company and used as receivedwithout further purication

22 Preparation of the Complexes e coordination com-pounds were prepared according to the general procedure(Scheme 1) [17]

Complex [Cu(2-amino-5-bromopyridine) 2(Cl) 2] (1) Onemmol of copper(II) chloride dehydrates and 21mmol of2-amino-5-bromopyridine (Scheme 1) were each dissolvedin 25mL of CH3OH e Cu(II) salt solution was thenadded slowly to the ligand solution thereby preventing anyprecipitation and the solution was ltered to remove anysolids Aer the solution stood for ve days the product wasseparated Yield about 85

Elemental analysis for CuC10H10N4Br2Cl2 (1) found C2489 H 221 N 1143 Cu 1368 Cal C 2500 H 210N 1166 Cu 1326

Complex [Co(2-amino-5-bromopyridine) 2 (Cl) 2] (2) Onemmol of cobalt(II) chloride dehydrates and 21mmol of 2-amino-5-bromopyridine each dissolved in 25mL of CH3OHe Co(II) salt solution was then added slowly to the

T 1 Crystal data and renement parameters for [Cu(2-amino-5-bromopyridine)2(Cl)2]

Empirical formula C10H10Br2Cl2CuN4

Formula weight 48048119879119879 (K) 296(2)Wavelength (Aring) 071073Crystal system MonoclinicSpace group 1198751198752 (1)119899119899119886119886 (Aring) 128921(4)119887119887 (Aring) 422090(10)119888119888 (Aring) 156291(4)120572120572 (∘) 90120573120573 (∘) 113730(2)120574120574 (∘) 90Vol (Aring3) 77857(4)119885119885 2Calculated density (Mgm3) 2050Absorption coefficient (mmminus1) 6868119865119865(000) 462Crystal size (mm) 054 times 009 times 004eta range for data collection (∘) 345 to 2811

minus17 le ℎ le 17Limiting indices minus5 le 119896119896 le 5

minus20 le 119897119897 le 20Reections collectedunique 232391902 [119877119877(int) = 00388]Completeness to theta 2811 997Renement method Full-matrix least squares on F2

Datarestraintsparameters 1902088Goodness-of-t on F2 0985Final 119877119877 indices [I gt 2120590120590(I)] 1198771198771 = 00329 1199081199081198771198772 = 00943119877119877 indices (all data) 1198771198771 = 00451 1199081199081198771198772 = 01026Largest diff peak and hole (esdotAminus3) 1210 and minus0866119882119882 119882 11198821198821198821198822(F2119900119900) + (00613119875119875)2 + 07908119875119875119875119875119875 119882 (F2119900119900 + 2 F2119862119862)1198823

119878119878 119882 119878 119882119908119908(F2119900119900 minus F2119862119862)2119882(Nobs minusNparam)119875

11198822

ligand solution thereby preventing any precipitation and thesolution was ltered to remove any solids Aer the solutionstood for ve days the product was separated Yield about79

Elemental analysis for CoC10H10N4Br2Cl2 (2) found C2557 H 217 N 1196 Co 1262 Cal C 2524 H 212N 1177 Co 1238

3 Physical Measurements

C H and N determination were undertaken using anElementar Analysis System Gmb H Vario EL II Cop-per and cobalt were determined on a Perkin-Elmer 2380Atomic Absorption Spectrophotometer Electronic spectrawere recorded on a Perkin-Elmer Lambda 900 spectropho-tometer using the diffuse reectance technique and MgOwas used as a reference FTIR spectra were obtained in the4000ndash300 cmminus1 range as KBr disks by using a Galaxy series

ISRN Inorganic Chemistry 3

T 2 Spectroscopic data for both complexes

Complex

IR (CundashN) cmminus1

UV-Vis (nm) ESR (powder) ESR (solution) 120583120583 (RT)IR (CundashCl) cmminus1

IR (CondashN) cmminus1

IR (CondashCl) cmminus1

(1)

459 720

215

119892119892|| = 232334 270 119892119892⟂ = 207 178

257 119860119860|| = 160 times 10minus4

119860119860N⟂ = 14 times 10minus4

(2)434 810 640

mdash mdash412

322 535 290259

T 3 Selected bond distances [Aring] and angles [∘]

Lenghts [Aring] Angles [∘]BrndashC(1) 1884(3) C(5)ndashN(2)ndashC(4) 1184(3)ClndashCu 22584(7) C(5)ndashN(2)ndashC(4) 1184(3)N(2)ndashC(5) 1348(4) C(4)ndashN(2)ndashCu 1268(2)N(2)ndashC(4) 1350(4) C(5)ndashC(1)ndashC(2) 1196(3)N(2)ndashCu 2039(2) C(5)ndashC(1)ndashBr 1191(3)C(1)ndashC(5) 1355(4) C(2)ndashC(1)ndashBr 1213(3)C(1)ndashC(2) 1389(5) C(3)ndashC(2)ndashC(1) 1183(3)C(2)ndashC(3) 1348(5) C(3)ndashC(2)ndashH(2) 1209C(2)ndashH(2) 09300 C(1)ndashC(2)ndashH(2) 1209C(3)ndashC(4) 1407(4) C(2)ndashC(3)ndashC(4) 1208(3)C(3)ndashH(3) 09300 C(2)ndashC(3)ndashH(3) 1196C(4)ndashN(1) 1334(4) C(2)ndashC(3)ndashH(3) 1196C(5)ndashH(5) 09300 N(1)ndashC(4)ndashN(2) 1192(3)N(1)ndashH(1A) 08600 N(1)ndashC(4)ndashC(3) 1207(3)N(1)ndashH(1B) 08600 N(2)ndashC(4)ndashC(3) 1201(3)CundashN(2)a 2039(2) N(2)ndashC(5)ndashC(1) 1228(3)CundashCl(a) 22584(7) N(2)ndashC(5)ndashH(5) 1186

C(1)ndashC(5)ndashH(5) 1186C(1)ndashC(5)ndashH(5) 1186C(4)ndashN(1)ndashH(1A) 1200C(4)ndashN(1)ndashH(1B) 1200H(1A)ndashN(1)ndashH(1B) 1200N(2)andashCundashN(2) 18000(14)N(2)andashCundashCl(a) 8866(7)N(2) ndashCundashCl(a) 9134(7)N(2)a1ndashCundashCl 9134(7)N(2)ndashCundashCl 8866(7)

Symmetry transformations used to generate equivalent atoms1 minusx minusy + 2 minusz + 1

FTIR 5000 spectrophotometer e spectra were calibratedusing the polystyrene bands at 3028 1601 and 1208 cmminus1 X-band electron paramagnetic resonance spectra were recordedof both powdered and frozen solutions of the complexes atboth room temperature and at liquid nitrogen temperaturein DMF or in DMSO on an IBM electron spin resonancespectrometer using DPPH (119892119892 119892 119892119892119892119892119892119892) as a standard e

NH2

N

N

M

Cl

Cl Br

Br

H2N

M = Cu Co

S 2 Structure of complexes

room temperature magnetic moment of each complex wasmeasured according to the Evans method H NMR determi-nation was carried out on a Bruker 300MHz spectrometer

4 Crystal Structure Determinationand Renement

e X-ray measurement of complex (1) was made on aBruker-Nonius X8 ApexII diffractometer equipped with aCCD area detector by sung graphite-monochromated Mok120572120572 radiation (120582120582 = 071073Aring) generated from a sealed tubesource Data were collected and reduced by SAINT sowarein the Bruker package [32] e structure was solved bydirect methods [33] and then developed by least squaresrenement on F119892 [34 35] OLEX2 program for Windowswas used to draw the structure [36] All non-H atoms wereplaced in calculated positions and rened as isotopic withthe ldquoriding-model techniquerdquoe complete conditions of thedata collection and structure are given in Table 1

5 Results and Discussion

51 Electronic Spectra e spectroscopic data for both com-pounds (Scheme 2) are presented in Table 2 e elec-tronic spectra of the complexes were obtained from a solidsample using the diffuse reectance technique Copper(II)compound (1) shows a broadband at about 720 nm is


band represents the ligand eld transition for the CuN2Cl2chromophore [37 38] e second absorption bands at270 nm are assigned to charge transfer from the nonbondingorbital of chloride ions to the vacant copper(II) d orbitals[37 39] e last absorption band observed at about 257 nmis associated with 120587120587 120587 120587120587lowast or 119899119899 120587 120587120587lowast transitions of theligand [40]On the basis of simplestmodel three spin-allowedbands are expected in tetrahedral cobalt(II) complexes thatis 4A2(F) 120587 4T2(F)

4A2(F) 120587 4T1(F) and4A2(F) 120587

4T1(P) Usually such complexes show two bands between 830and 625 nm which can be assigned to 4A2(F) 120587

4T2(F) and4A2(F) 120587 4T1(F) respectively

4A2(F) 120587 4T1(P) is usuallyobserved as a well-dened shoulder at about 550 nm [41]e UV-Vis spectra of complex (2) were obtained from solidsample using diffuse reectance technique e compoundshows a broad shoulder with bands at 810 640 and 535 nmis due to 119889119889 120587 119889119889 transitions Absorption at 290 is assignedto charge transfer from the nonbonding orbital of chlorideions to half-lled d orbitals of cobalt(II) [42] Absorption at259 nm is associated with 120587120587 120587 120587120587lowast or 119899119899 120587 120587120587lowast transitions ofthe ligand [43 44]

52 Infrared Spectra e IR spectra of the free ligand andthe complexes were obtained in the range of 4000ndash300 cmminus1All the bands present in the IR spectra of the free ligand werealso observed in the spectra of the complexes Based on datafrom earlier reports [45 46] we assigned bands at 459 and434 cmminus1 for (1) and (2) respectively to M-N vibrations M-Cl vibrations for (1) and (2) are assigned to 334 and 322 cmminus1respectively [47 48]

53 Magnetic Moment e magnetic moment of both com-plexes were determined by the Evans method [49] ismethod is based on the principle that the position of agiven proton resonance (t-butyl alcohol) in the spectrum ofa molecule is dependent on the bulk susceptibility of themedium in which the molecule is founde shi of a protonresonance line of an inert substance due to the presence ofparamagnetic ions is given by theoretical expression

Δ119907119907119907119907o

= 100765210076522120587120587310076681007668 10076681007668120594120594119907119907 minus 120594120594119907119907prime10076651007665 (1)

In this equation Δ119907119907 is the shi 119907119907o is the applied eld120594120594119907119907 is the volume susceptibility of the solution containingparamagnetic ions and 120594120594119907119907prime is the volume susceptibility of thereference solutione values of 178 and 412 were found forcomplexes (1) and (2) respectively

54 Electron Spin Resonance e electron spin resonance(ESR) spectra of complex (1) in powder and in frozensolution form were recorded at X-band frequencies at roomtemperature and at liquid nitrogen temperature to aid indetermining the ground-state conguration of copper(II)ions In the solid state the spectra shows only a weak andbroad signal (119892119892ave = 215) Such behavior is also found inthe literature [50] e observed frozen solution (77K) ESRspectra of the compound in DMSO or DMF shows two bands

600

0

minus500

minus1000

Inte

nsi

ty

2400 3400

Field (gauss)

F 1 ESR spectra of Cu(II) complex in DMF at liquid nitrogentemperature

located at 119892119892|| = 232 and 119892119892⟂ = 207 corresponding to theΔ119872119872S = plusmn1 transition is feature (Figure 1) is typical forcopper(II) complexes e 119892119892|| gt 119892119892⟂ gt 20023 also exhibitlarge parallel hyperne splitting and are associated with the1198891198891199091199092minus1199101199102 ground state [51] In the spectrum of complex theparallel region is clearly resolved and all four transitionsderived from the Cu (I 32) hyperne splitting can bedirectly observed ese hyperne lines for complexes splitthe 119892119892I signal with an average spacing of 160 times 10minus4 cmminus1 Inthe perpendicular region the spectrum is not well resolvedalthough some superhyperne structure is observede lackof clear resolution in this spectral region is presumably dueto the large number of overlapping Δ119872119872I = 0 and Δ119872119872I gt 0transitions and to the large intrinsic widths of the individualtransitions e structure observed in the perpendicularregion of the spectra is due to nitrogen superhypernesplitting of the ligandseAN⟂ value ofasymp14times 10

minus4 cmminus1 andthe presence of three peaks for the nitrogen superhypernestructure of the complex are in accordance with expectationsfor two N donors per copper(II) ions [52 53]

6 Description of the CrystalStructure of Complex (1)

esolid-state structure of complex (1) determined by single-crystal X-ray diffraction together with atom labeling isshown in Figure 2 Selected bond lengths and bond angles arepresented in Table 3 Crystallographic data and structure

Renement parameters are summarized in Table 1 estructure of complex (1) consists of a Cu surrounded bytwo ligands and two chlorides In this complex Cu(II) has aslightly distorted square planar geometry with trans positionof two halides e structure is essentially a D2h symmetricand the copper(II) ion is four coordinate as expected withtrans halides e CundashN distances are 2039Aring and CundashCl22584Aring e angles NndashCundashN and ClndashCundashCl are 1800(∘) while the N(2)andashCundashCl(a) and N(2)ndashCundashCl angles are8866 (∘) e angles N(2)ndashCundashCl(a) and N(2)andashCundashCl are9134 (∘) Four-coordinate copper(II) compounds with two


Cl

C1

N1

N2N2a

H1B

H1A

C2

C3 C4

C5

Cla

Br

Cu

F 2 Crystal structure of complex [Cu(2-amino-5-bro-mopyridine)2(Cl)2]

different ligands are almost distorted square planar symmetryfrom a coupling between electronic and vibration wavefactions that lower the ground-state energy [54]

Acknowledgment

e authors (R A Ahmadi F Hasanvand and S Amani)thank the Research Council of Arak University for nancialsupport of this research

References

[1] G F Kokoszka and R W Duerst ldquoEpr studies of exchangecoupledmetal ionsrdquoCoordination Chemistry Reviews vol 5 no2 pp 209ndash244 1970

[2] P J Hay J Cibeault and R Hoffmann ldquoOrbital interactionsin metal dimer complexesrdquo Journal of the American ChemicalSociety vol 97 no 17 pp 4884ndash4899 1975

[3] J Reedijk ldquoHeterocyclic nitrogen-donor ligandsrdquo in Compre-hensive Coordination Chemistry G Wilkinson Ed vol 2 pp73ndash98 Pergamon Oxford UK 1987

[4] S R Collinson and D E Fenton ldquoMetal complexes of bibrac-chial Schiff basemacrocyclesrdquoCoordination Chemistry Reviewsvol 148 pp 19ndash40 1996

[5] S Mandal G Das R Singh R Shukla and P K BharadwajldquoSynthesis and studies of Cu(II)-thiolato complexes bioinor-ganic perspectivesrdquo Coordination Chemistry Reviews vol 160pp 191ndash235 1997

[6] W Kaim J Rall and J Rall ldquoCopper a ldquomodernrdquo bioelementrdquoAngewandte Chemie vol 35 no 1 pp 43ndash60 1996

[7] P Singh D Y Jeter W E Hateld and D J Hodg-son ldquoOut-of-plane interactions in parallel-planar copper(II)dimerse structure andmagnetic properties of dibromobis(2-methylpyridine)copper(II)rdquo Inorganic Chemistry vol 11 no 7pp 1657ndash1661 1972

[8] L Yang D C Crans S M Miller et al ldquoCobalt(II) andcobalt(III) dipicolinate complexes solid state solution and invivo insulin-like propertiesrdquo Inorganic Chemistry vol 41 no19 pp 4859ndash4871 2002

[9] F Saker J Ybarra P Leahy R W Hanson S C Kalhan andF Ismail-Beigi ldquoGlycemia-lowering effect of cobalt chloride inthe diabetic rat role of decreased gluconeogenesisrdquo AmericanJournal of Physiology vol 274 no 6 pp E984ndashE991 1998

[10] J Ybarra A Behrooz A Gabriel M H Koseoglu and FIsmail-Beigi ldquoGlycemia-lowering effect of cobalt chloride in thediabetic rat increased GLUT1 mRNA expressionrdquo Molecularand Cellular Endocrinology vol 133 no 2 pp 151ndash160 1997

[11] V G Yuen C Orvig and J H McNeill ldquoGlucose-lowering effects of a new organic vanadium complexbis(maltolato)oxovanadium(IV)rdquo Canadian Journal ofPhysiology and Pharmacology vol 71 no 3-4 pp 263ndash2691993

[12] J Fugono H Yasui and H Sakurai ldquoPharmacokinetic study ongastrointestinal absorption of insulinomimetic vanadyl com-plexes in rats by ESR spectroscopyrdquo Journal of Pharmacy andPharmacology vol 53 no 9 pp 1247ndash1255 2001

[13] N Cohen M Halberstam P Shlimovich C J Chang HShamoon and L Rossetti ldquoOral vanadyl sulfate improveshepatic and peripheral insulin sensitivity in patients withnon-insulin-dependent diabetes mellitusrdquo Journal of ClinicalInvestigation vol 95 no 6 pp 2501ndash2509 1995

[14] A B Golne M E Patti L Zuberi et al ldquoExcess weightgain and obesity science and researchrdquoMetabolism Clincal andExperimental vol 49 pp 400ndash410 2000

[15] D C Crans ldquoChemistry and insulin-like properties of vana-dium(IV) and vanadium(V) compoundsrdquo Journal of InorganicBiochemistry vol 80 no 1-2 pp 123ndash131 2000

[16] D C Crans L Yang T Jakusch and T Kiss ldquoAqueous chem-istry of ammonium (dipicolinato)oxovanadate(V) the rstorganic vanadium(V) insulin-mimetic compoundrdquo InorganicChemistry vol 39 no 20 pp 4409ndash4416 2000

[17] J C Stevens P J Jackson W P Schammel G G Christophand D H Busch ldquoSynthesis and structure of totally syntheticcoboglobin modelsrdquo Journal of the American Chemical Societyvol 102 no 9 pp 3283ndash3285 1980

[18] Y Gok ldquoSynthesis and characterization of new (EE)-dioximesand their cobalt(III) complexes containing crown ether moi-etiesrdquo Polyhedron vol 13 no 11 pp 1793ndash1800 1994

[19] K A Lance K A Goldsby and D H Busch ldquoEffective newcobalt(II) dioxygen carriers derived from dimethylglyoxime bythe replacement of the linking protons with BF2+rdquo InorganicChemistry vol 29 no 22 pp 4537ndash4544 1990

[20] C Srivanavit and D G Brown ldquoIsotropic proton shis forCo(salen)rdquo Journal of the American Chemical Society vol 98no 15 pp 4447ndash4449 1976

[21] N Kumaraguru K Santhakumar S Arunachalam and MN Arumugham ldquoSynthesis characterization and micellizationbehaviour of some surface active mixed-ligand complexes ofcobalt(III)rdquo Polyhedron vol 25 no 17 pp 3253ndash3260 2006

[22] P Nagababu J Naveena Lavanya Latha P Pallavi S Harishand S Satyanarayana ldquoStudies on antimicrobial activity ofcobalt(III) ethylenediamine complexesrdquo Canadian Journal ofMicrobiology vol 52 no 12 pp 1247ndash1254 2006

[23] M A Zharnikova A E Balakirev V E Maizlish and GP Shaposhnikov ldquoCobalt(II) tetraaminotetranitrophthalocya-nine and its N-acyl derivativesrdquo Russian Journal of GeneralChemistry vol 72 no 1 pp 131ndash132 2002

[24] A E Balakirev V E Maizlish O V Balakireva G PShaposhnikov V V Bykova and N V Usolrsquotseva ldquoMetalphthalocyanines with undecyloxybenzoic acid residues andtheir mesomorphic propertiesrdquo Russian Journal of GeneralChemistry vol 74 no 2 pp 295ndash299 2004


[25] B M Hoffman and D H Petering ldquoCoboglobins oxygen-carrying cobalt-reconstituted hemoglobin andmyoglobinrdquoPro-ceedings of the National Academy of Sciences of the United Statesof America vol 67 no 2 pp 637ndash643 1970

[26] M Kurmoo ldquoMagnetic metal-organic frameworksrdquo ChemicalSociety Reviews vol 38 no 5 pp 1353ndash1379 2009

[27] F Lloret M Julve J Cano R Ruiz-Garcia and E PardoldquoSyntheses and structures of three complexes of formu-las [L3Co(1205831205832-O2P(Bn)2)3CoL

prime][LPrime] featuring octahedral and

tetrahedral cobalt(II) geometries variable-temperature mag-netic susceptibility measurement and analysis on [(py)3Co(1205831205832-O2PBn2)3Co(py)][ClO4]rdquo Inorganic Chemistry vol 361 pp3432ndash3445 2008

[28] S Langley M Helliwell R Sessoli S J Teat and R EWinpenny ldquoSynthesis and structural and magnetic character-ization of cobalt(II) phosphonate cage compoundsrdquo InorganicChemistry vol 47 no 2 pp 497ndash507 2008

[29] A Ferguson A Parkin J Sanchez-Benitez K Kamenev WWernsdorfer and M Murrie ldquoA mixed-valence Co7 single-molecule magnet with C3 symmetryrdquo Chemical Communica-tions no 33 pp 3473ndash3475 2007

[30] H Miyasaka M Julve M Yamashita and R Cleacuterac ldquoSlowdynamics of the magnetization in one-dimensional coordina-tion polymers single-chain magnetsrdquo Inorganic Chemistry vol48 no 8 pp 3420ndash3437 2009

[31] E Pardo R Ruiz-Garciacutea F Lloret et al ldquoLigand designfor heterobimetallic single-chain magnets synthesis crystalstructures and magnetic properties of MIICuII (M = Mn Co)chains with sterically hindered methyl-substituted phenyloxa-mate bridging ligandsrdquo Chemistry A European Journal vol 13no 7 pp 2054ndash2066 2007

[32] Bruker AXS Inc SAINT (Version 602) Madison Wisc USA1999

[33] M C Burla R Caliandro M Camalli et al ldquo2-amino-3-methyl-6-[methyl(phenyl)amino]-5-nitropyrimidin-4(3H)-one polarized molecules within hydrogen-bonded sheetsrdquoJournal of Applied Crystallography vol 38 pp 381ndash388 2005

[34] G M Sheldrick SHELXL97 Grogram For Crystal StructureRenement University of Goumlttingen Goumlttingen Germany1997

[35] SHELXT LN Version 510 Bruker Analytical X-ray MadisonWisc USA 1998

[36] L J Farrugia ldquoORTEP-3 for windowsmdasha version of ORTEP-III with a graphical user interface (GUI)rdquo Journal of AppliedCrystallography vol 30 no 5 p 565 1997

[37] L M Berreau V G Young and L K Woo ldquoSynthesischaracterization and reactivity of suldo- and sele-nidomolybdenum(IV) porphyrin complexes X-ray structure ofsuldo(5101520-tetratolylporphyrinato)molybdenum(IV)rdquoInorganic Chemistry vol 34 no 13 pp 3485ndash3490 1995

[38] A B P Lever Inorganic Electronic Spectroscopy ElsevierAmsterdam e Netherlands 2nd edition 1984

[39] K R J omas P armaraj V Chandrasekhar S R Scottand A Wallace Cordes ldquoFive-coordinate copper(II) complexesof GEM-N3P3Ph2(dmpz)4rdquo Polyhedron vol 14 no 8 pp977ndash982 1995

[40] N A Bailey D E Fenton R Moody et al ldquoComplexesof ligands providing endogenous bridges Part 4 Copper(II)complexes of macrocyclic Schiff bases derived from 26-diacetylpyridine and 1n-diamino-119899119899prime-hydroxyalkanes (119899119899119899 119899119899prime =

32 42 and 53) synthesis properties and structuresrdquo Jour-nal of the Chemical Society Dalton Transactions no 11 pp2519ndash2529 1987

[41] J Comarmond P Plumereacute J M Lehn et al ldquoDinuclearcopper(II) cryptates of macrocyclic ligands synthesis crystalstructure andmagnetic propertiesMechanism of the exchangeinteraction through bridging azido ligandsrdquo Journal of theAmerican Chemical Society vol 104 no 23 pp 6330ndash63401982

[42] F Hasanvand A Hoseinzadeh J Zolgharnein and S AmanildquoSynthesis and characterization of two acetato-bridgeddinuclear copper(II) complexes with 4-bromo-2-((4 or 6-methylpyridin-2-ylimino)methyl)phenol as ligandrdquo Journal ofCoordination Chemistry vol 63 no 2 pp 346ndash352 2010

[43] S A Komaei G A Van Albada and J Reedijk ldquoSynthesisspectroscopic and magnetic properties of methoxo-bridgedcopper(II) complexes with 2-amino-4-methylpyridine as theligandrdquo Transition Metal Chemistry vol 24 no 1 pp 104ndash1071999

[44] L Rodriacuteguez E Labisbal A Sousa-Pedrares et al ldquoCoordi-nation chemistry of amine bis(phenolate) cobalt(II) nickel(II)and copper(II) complexesrdquo Inorganic Chemistry vol 45 no 19pp 7903ndash7914 2006

[45] M G B Drew P C Yates F S Esho et al ldquoDicop-per(II) complexes of a binucleating N4 macrocycle containingmono- and di-atomic bridges Magnetic interactions medi-ated by alkoxo- and diaza-bridging ligands Crystal struc-tures of [Cu2(L

1)(pz)2][ClO4]2 [Cu2(L1)(OEt)2(NCS)2] and

[Cu2(L1)(OMe)2(MeCN)2][BPh4]2rdquo Journal of the Chemical

Society Dalton Transactions no 12 pp 2995ndash3003 1988[46] F E Mabbs ldquoSome aspects of the electron paramagnetic

resonance spectroscopy of d-transition metal compoundsrdquoChemical Society Reviews vol 22 no 5 pp 313ndash324 1993

[47] J E Weder T W Hambley B J Kennedy et alldquoAnti-inammatory dinuclear copper(ii) complexes withindomethacin synthesis magnetism and EPR spectroscopyCrystal structure of the NN-dimethylformamide adductrdquoInorganic Chemistry vol 38 no 8 pp 1736ndash1744 1999

[48] J Stankowski ldquoOrbital dynamics of the CuXn complex insolidsrdquo Journal of Molecular Structure vol 597 no 1ndash3 pp109ndash119 2001

[49] D F Evans ldquoe determination of the paramagnetic suscepti-bility of substances in solution by nuclear magnetic resonancerdquoJournal of the Chemical Society vol 2003ndash2005 1959

[50] F Hasanvand N Nasrollahi A Vajjed and S Amani ldquoSyn-thesis spectroscopy and characterization of four alkoxo-bridged dinuclear copper(II) complexes containing 2-amino-4-methylpyridine or 2-amino-4-cyanopyridine as the ligandsrdquoMalaysian Journal of Chemistry vol 12 no 1 pp 27ndash32 2010

[51] J Manzur H Mora A Vega et al ldquoCopper(II) complexeswith new polypodal ligands presenting axial-equatorialphenoxo bridges 2-[(bis(2-pyridylmethyl)-amino)methyl]-4-methylphenol 2-[(bis(2-pyridylmethyl)-amino)methyl]-4-methyl-6-(methylthio)phenol examples of ferromagneticallycoupled bi- and trinuclear copper(II) complexesrdquo InorganicChemistry vol 46 no 17 pp 6924ndash6932 2007

[52] D Kovala-Demertzi D Skrzypek B Szymańska A Galaniand M A Demertzis ldquoEPR spectroscopic study of a dinuclearcopper(II) complex of tolfenamic acidrdquo Inorganica ChimicaActa vol 358 no 1 pp 186ndash190 2005

[53] F Hasanvand R Arab Ahmadi and S Amani ldquoSynthesisspectroscopy and magnetic characterization of ve dinuclear


copper(II) complexes with 2 3 or 4-pyridinemethanol as theligandrdquo Journal of Sciences Islamic Republic of Iran vol 23 no1 pp 37ndash43 2012

[54] Z Fu and T Chivers ldquoTwo new high-nuclearity copper(II)chloride oligomers with herringbone stacking patterns synthe-sized by in situ temptationrdquoCanadian Journal of Chemistry vol84 no 2 pp 140ndash145 2006

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

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Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


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Medicinal ChemistryInternational Journal of


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Applied ChemistryJournal of



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Analytical ChemistryInternational Journal of


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Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


NH2N

Br

S 1 Structure of ligand

medicine magnetic resonance imaging and drug delivery[21] Cobalt ethylenediamine complexes are potent antimi-crobial agents [22] Low-spin cobalt porphyrins [23 24] are ofinterest since cobalt-substituted hemoglobin ldquocoboglobinrdquobinds oxygen in a cooperative fashion [25] e growth ofcobalt chemistry has necessitated the development of modelsto account for and predict the spectroscopic properties ofcobalt(II) complexes Cobalt(II) compounds have interestingmagnetochemistry as shown in a recent review on magneticmetal-organic frameworks [26] Strong magnetic anisotropyof high-spin cobalt(II) is at the origin of the increasinginterest in polynuclear compounds containing this metal ion[27] Several examples of high-nuclear complexes with six-coordinate cobalt(II) behaving as single molecule magnetsand single chain magnets have been reported [28ndash31] Wehave been interested in copper(II) and cobalt(II) complexeswith 2-amino-5-bromopyridine as ligand Such complexeshave potential for antibacterial activities andwewill focus onthis subject in the future e complexes were synthesized ina one-step synthesis and characterized by elemental analysisFourier transform infrared (FTIR) electronic spectra roomtemperature magnetic moments and a crystal structure

2 Experimental

21 Chemicals All of the chemicals and solvents were pur-chased fromMerck Chemical Company and used as receivedwithout further purication

22 Preparation of the Complexes e coordination com-pounds were prepared according to the general procedure(Scheme 1) [17]

Complex [Cu(2-amino-5-bromopyridine) 2(Cl) 2] (1) Onemmol of copper(II) chloride dehydrates and 21mmol of2-amino-5-bromopyridine (Scheme 1) were each dissolvedin 25mL of CH3OH e Cu(II) salt solution was thenadded slowly to the ligand solution thereby preventing anyprecipitation and the solution was ltered to remove anysolids Aer the solution stood for ve days the product wasseparated Yield about 85

Elemental analysis for CuC10H10N4Br2Cl2 (1) found C2489 H 221 N 1143 Cu 1368 Cal C 2500 H 210N 1166 Cu 1326

Complex [Co(2-amino-5-bromopyridine) 2 (Cl) 2] (2) Onemmol of cobalt(II) chloride dehydrates and 21mmol of 2-amino-5-bromopyridine each dissolved in 25mL of CH3OHe Co(II) salt solution was then added slowly to the

T 1 Crystal data and renement parameters for [Cu(2-amino-5-bromopyridine)2(Cl)2]

Empirical formula C10H10Br2Cl2CuN4

Formula weight 48048119879119879 (K) 296(2)Wavelength (Aring) 071073Crystal system MonoclinicSpace group 1198751198752 (1)119899119899119886119886 (Aring) 128921(4)119887119887 (Aring) 422090(10)119888119888 (Aring) 156291(4)120572120572 (∘) 90120573120573 (∘) 113730(2)120574120574 (∘) 90Vol (Aring3) 77857(4)119885119885 2Calculated density (Mgm3) 2050Absorption coefficient (mmminus1) 6868119865119865(000) 462Crystal size (mm) 054 times 009 times 004eta range for data collection (∘) 345 to 2811

minus17 le ℎ le 17Limiting indices minus5 le 119896119896 le 5

minus20 le 119897119897 le 20Reections collectedunique 232391902 [119877119877(int) = 00388]Completeness to theta 2811 997Renement method Full-matrix least squares on F2

Datarestraintsparameters 1902088Goodness-of-t on F2 0985Final 119877119877 indices [I gt 2120590120590(I)] 1198771198771 = 00329 1199081199081198771198772 = 00943119877119877 indices (all data) 1198771198771 = 00451 1199081199081198771198772 = 01026Largest diff peak and hole (esdotAminus3) 1210 and minus0866119882119882 119882 11198821198821198821198822(F2119900119900) + (00613119875119875)2 + 07908119875119875119875119875119875 119882 (F2119900119900 + 2 F2119862119862)1198823

119878119878 119882 119878 119882119908119908(F2119900119900 minus F2119862119862)2119882(Nobs minusNparam)119875

11198822

ligand solution thereby preventing any precipitation and thesolution was ltered to remove any solids Aer the solutionstood for ve days the product was separated Yield about79

Elemental analysis for CoC10H10N4Br2Cl2 (2) found C2557 H 217 N 1196 Co 1262 Cal C 2524 H 212N 1177 Co 1238

3 Physical Measurements

C H and N determination were undertaken using anElementar Analysis System Gmb H Vario EL II Cop-per and cobalt were determined on a Perkin-Elmer 2380Atomic Absorption Spectrophotometer Electronic spectrawere recorded on a Perkin-Elmer Lambda 900 spectropho-tometer using the diffuse reectance technique and MgOwas used as a reference FTIR spectra were obtained in the4000ndash300 cmminus1 range as KBr disks by using a Galaxy series



Complex





(1)

459 720

215

119892119892|| = 232334 270 119892119892⟂ = 207 178

257 119860119860|| = 160 times 10minus4

119860119860N⟂ = 14 times 10minus4

(2)434 810 640

mdash mdash412

322 535 290259






NH2

N

N

M

Cl

Cl Br

Br

H2N

M = Cu Co









4A2(F) 120587 4T1(F) and4A2(F) 120587






Δ119907119907119907119907o

= 100765210076522120587120587310076681007668 10076681007668120594120594119907119907 minus 120594120594119907119907prime10076651007665 (1)



600

0

minus500

minus1000

Inte

nsi

ty

2400 3400

Field (gauss)








Cl

C1

N1

N2N2a

H1B

H1A

C2

C3 C4

C5

Cla

Br

Cu



Acknowledgment


References









































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



Complex





(1)

459 720

215

119892119892|| = 232334 270 119892119892⟂ = 207 178

257 119860119860|| = 160 times 10minus4

119860119860N⟂ = 14 times 10minus4

(2)434 810 640

mdash mdash412

322 535 290259






NH2

N

N

M

Cl

Cl Br

Br

H2N

M = Cu Co









4A2(F) 120587 4T1(F) and4A2(F) 120587






Δ119907119907119907119907o

= 100765210076522120587120587310076681007668 10076681007668120594120594119907119907 minus 120594120594119907119907prime10076651007665 (1)



600

0

minus500

minus1000

Inte

nsi

ty

2400 3400

Field (gauss)








Cl

C1

N1

N2N2a

H1B

H1A

C2

C3 C4

C5

Cla

Br

Cu



Acknowledgment


References









































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



4A2(F) 120587 4T1(F) and4A2(F) 120587






Δ119907119907119907119907o

= 100765210076522120587120587310076681007668 10076681007668120594120594119907119907 minus 120594120594119907119907prime10076651007665 (1)



600

0

minus500

minus1000

Inte

nsi

ty

2400 3400

Field (gauss)








Cl

C1

N1

N2N2a

H1B

H1A

C2

C3 C4

C5

Cla

Br

Cu



Acknowledgment


References









































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Cl

C1

N1

N2N2a

H1B

H1A

C2

C3 C4

C5

Cla

Br

Cu



Acknowledgment


References









































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

3ftfbsdi sujdmf 4zouiftjt 4qfdusptdpqz …downloads.hindawi.com/archive/2013/426712.pdfpg (&. /...

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