Indian Journal of ChemistryVol. 23A. December 1984. pp. 1041-1043

Hetero-binuclear Schiff BaseComplexes of Copper(II) & Nickel(II)

with Zinc(II) or Cadmium(II)

C \-1 DANI

Research and Control Laboratory. Rourkela Steel Plant.Rourkela 769011

and

A K DAS·

Department of Chemistry. Government College.Rourke1a 769004

-nred I vl arcn 1984: re cised and accepted 13 August 1984

Hetero-binuclear schiff base complexes of the types [Cu Ll \1X1]and ["liL'\1X1J. where LH = schiff base derived from salicylal-dehyde and ammonia: !vl = Zm l l] or Cd(II); X =CI-. "lO.l or CIO~;and L'H2 = schiff base derived from salicylaldehyde and 0-

phenylenediamine have been prepared and characterised byelemental analyses. spectral data OR and electronic) and magneticsusceptibility measurement>. Square-planar configuration aroundCu(lI) and Ni(II) has been proposed for these complexes.

Although considerable attention has been paid to thestudy! - 6 of homo-bi- and tri-nuclear transition metalcomplexes of schiff bases. reports) on heteronucleartransition metal complexes of such ligands are few. Incontinuation of our recent report 7 on some bimetallictetra-(morpholine-4-carbodithioates). we report in thepresent note the results of our investigations on a fewhetero-binuclear schiff base complexes of the types[Cul2MX2] and [NiL'MX!J, where LH =schilT basederived from salicylaldehyde and ammonia; \1= Zn(lI) or CdOI): X = CI-. NO:3 or CIO 4: and L'H2= schiff base derived from salicylaldehyde and 0-

phenylenediamine.All the chemicals used were of AR grade.

Preparation o!'[CIIL2MX2]

The parent complex. [CuL2]. was preparedaccording to the reported method" by refluxingtetraaminecopper(lI) complex (in solution) withethanolic solution of salicylaldehyde in 1:2 molar ratiofor one hour. The green coloured compound thusobtained was filtered. washed with ethanol and etherand dried ill raCl/o. The purity of the complex wasestablished by estimating copper and nitrogen [Found:Cu. 20.41; N. 8.60. CUCI~ HI2N202 requires: Cu.20.93; N. 9.22" oJ.

A suspension of [Cu L2] in chloroform was thenadded to a solution of zincrll) or cadmium(lI) salt inethanol in I: I stoichiometric ratio and the mixture wasrefluxed for 2 hr. The resulting solid complexes were

filtered, washed several times with chloroform andfinally dried in vacuo.

Preparation of [NiL' MX 2]The schiff base, L'H2, was prepared as reported".

The parent complex, [Nil'], was obtained aschocolate-red solid by relluxing nickel(II) chloridehexahydrate with the schilT base (L'H2) in I: I molarratio in ethanol medium for 1.5 hr followed by cooling.The resulting solid was filtered, washed with ethanoland ether and dried ill vacuo. Its purity was checked bydetermining nickel and nitrogen contents [Found: Ni,15.80; N. 7.43. Ni CZOH14N202 requires: Ni, 15.92; N,7.59 o/~J.

A solution of [Nil'] in chloroform was then mixedwith an ethanolic solution of zinc(II) or cadmium(II)salt in I:l stoichiometric ratio and the mixture wasrefluxed for 1.5 hr. The resulting solid compounds werefiltered. washed thoroughly with chloroform and thendried in l'acuo.

The purity of the isolated complexes was ascertainedby elemental analyses. Copper, nickel. zinc, cadmiumand chloride were estimated by standard methods.Carbon and hydrogen were estimated microanalyti-cally. Magnetic measurements were carried out by aGouy balance using Hg[Co(NCS)4] as the cali brant.The diamagnetic corrections were made using Pascal'sconstants!". IR spectra were recorded on a PerkinElmer spectrophotometer-577 in the range 4000-600cm - 1in KBr. Electronic spectra of the complexes wererecorded in the solid state with the help of a UnicamSP-500 spectrophotometer using nujol mull technique.

Analytical data (Table I) support the proposedformulations of the complexes. All the copper andnickel complexes are amorphous powders having highmelting points (> 250'C). They are almost insoluble inwater and common organic solvents.

The room temperature magnetic moment values ofthe present Cu(II) complexes (1.82-2.08 B.M.)correspond to the presence of one unpaired electron.However. no specific conclusion regarding theirstereochemistry can tie drawn from the magneticmoment data. All the Ni(II) complexes are found to bediamagnetic. suggesting their square-planargeometryll.

The parent Cu(II) complex, [Cul2], exhibits IRbands at 3290. 3255. 1610 and 1515 cm -. which may beattributed to v(N - H). v(C = N) and v(C - 0)respectively. In the parent Ni(II) complex, [Nil'], V(C=N) and v(C-O) appear at 1595 and 1503 cm-Irespectively. These data suggest that the metal is

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INDIAN J. CHEM., VOL. 23A, DECEMBER 1984

Table i-Analytical and Physical Data of Hetero-binuclear Schiff Base Complexes ofCopper(lI) & Nickel(II) with Zinc(II) or

Cadmium(Il)Compound Colour Found (calc.), ~~ IJ.".

(B.M.)Ni/Cu Zn/Cd C H CI

[NiL'ZnCI2J Reddish-yellow 11.02 12.48 47.11 2.38 13.88 Diamagnetic(11.62) (12.94) (47.52) (2.77) (14.04)

[NiL'Zn(N03hJ Deep-red 10.36 10.98 42.85 2.11 do(10.51) (11.71) (43.00) (2.50)

[NiL'Zn(CI04hJ Orange 9.10 10.98 37.24 2.08 do(9.27) (10.32) (37.91) (2.21)

[NiL'CdCI2J Orange-red 9.81 20.94 42.91 2.32 12.12 do(10.63) (20.36) (43.47) (2.53) (12.84)

[NiL'Cd(N03hJ Orange 10.25 19.00 39.11 2.01 do(9.70) (18.57) (39.66) (2.31)

[NiL'Cd(CI04hJ Orange-red 8.28 16.59 34.89 1.88 do(8.63) (16.52) (35.29) (2.05)

[CuL2ZnCI2J Grey 14.32 13.98 37.85 2.14 15.69 2.08(14.44) (14.86) (38.19) (2.72) (16.12)

[CuL2Zn(N03hJ Leaf-green 12.29 13.10 34.28 2.31 1.95(12.89) (13.26) (34.08) (2.43)

[CuL]Zn(CI04hJ Yellowish-green 11.98 11.01 29.01 1.92 1.82(11.18) (11.51) (29.58) (2.11)

[CuL2CdCI2J Grey 13.70 22.68 33.98 2.59 14.20 1.92(13.05) (23.08) (34.50) (2.46) (14.56)

[CuL2Cd(N03hJ Yellowish-green 11.21 20.18 30.68 1.86 2.05(11.76) (20.81) (31.11) (2.22)

[CuL2Cd(CI04hJ Pale-green 10.90 18.01 27.12 1.39 1.85(10.33) (18.28) (27.32) (1.95)

coordinated through C = Nand C - 0 in both theparent complexes. The involvement of phenolic groupsin the chelate formation is further confirmed by theabsence of vOH in both the parent complexes. Theoccurrence of v(C -0) bands at 1535-1540 and 1515-1530 cm-I in the [CuL2MX2] and [NiL'MX2]complexes respectively as compared to that of theparent complexes [CuL2] and [NiL'] respectively at1515 and 1503 em - I, suggests 1.6,12 bridging throughphenolic 0 -. Other bands due to schiff base in theparent complexes are also modified slightly (5-10em -I) in the heterobinuc!ear complexesl,6,12. Theabsence of V3 band of ionic nitrate around 1360 ern - 1and the presence of two strong bands at -1510 and-1300 cm -I due to Vas N02 and VS N02 respectively,reveal the un identate nature of coordinated nitrategrou ps 13- 17 in the nitrate complexes. The perchloratecomplexes of Nitl l) exhibit three sharp bands in theregion -1100 cm -I supporting the coordinatednature of perchlorate groupl8 -21. Further, the absenceof a broad band in the region llOO cm -I in the IRspectra of Cu(II) complexes definitely suggests thecoordinated behaviour of ClO 4'

The solid state electronic spectra of [CuL2MX2]type of complexes in nujol mull exhibit a strong charge-transfer band at 27.7 kK and ad - d transition around16.4 kK assignable to overlapping transitions 2819

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-o2A1g, 281g-0282g and 2819-o2Ei in a square planarenvironment around Cu(II)21,22. Nickel complexes[NiL'MX2] give rise to two strong charge-transferbands at - 26.6 and - 21.0 kK and a broad ligand fieldband around 16.6 kK suggesting their square-planargeometry. The broad band at 16.6 kK represents agroup of two to three transitions IAlg-oIA2g, IAlg

-0 182g, IA Ig-o 1Eg in square-planar geometry aroundNi(II)22,23, in conformity with the diamagnetic natureof the complexes. Further, the electronic spectra of thecomplexes [CuL2MX2] and [NiL'MX2] resemblethose of square-planar complexes [CuL2] and [NiL']respectively.

Hence, on the basis of analytical, magnetic moment,IR and electronic spectral data and stereochemical

consideration+P the following structures (I & II) aresuggested for the present hetero-binuclear schiff basecomplexes.

The authors are thankful to Prof. D.V. Ramana Rao,Head of the Chemistry Department, RegionalEngineering College, Rourkela for his interest, themanagement of Rourkela Steel Plant for providingnecessary facilities and to the RSIC and CDRI,Lucknow for running IR spectra of the complexes.

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1805.2 Kato M, Imai K, Muto Y, Tokii T & Jonasen H B,J inorg nucl

Chem, 35 (1973) 109.3 Sinn E & Harris C M, Coord chem Rev, 4 (1969) 391.4 Bhattacharya P K, J Indian chem Soc, 59 (1982) 505.5 Patel K V & Bhattacharya P K, Indian J Chem, 21A (1982) 674.

6 Patel K V & Bhattacharya P K, IndianJ Chem, 21A (1982) IllO.

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IIYUlilL..llIC . L\ l-'U~lLl"t: ~11I1l lit "'tV-"'t7l.:1l1 III lilt: "\1"

- N) band in the complexes as compared to its position(X7X em - I) in the ligand supports the unidentatecoordination of the (N - N) moiety of phenyl-hydruzine?", The bands observed in the regions 1590-1560 and 1515-14XOcm-1 in the spectra of all the

NOTES

10 Figgis B N & Lewis J, Modern coordination chemistry, edited by JLewis & R G Wilkins (Interscience, London) 1960,402.

II Nishida Y, Sumita A & Kida S, Bull chem Soc Japan, 50 (1977)759.

12 Harris C M & Sinn E, J inorg nucl Chem, 30 (1968) 2723.13 Addission C C & Logan N, Adv inorg Radiochem, 6 (1964) 95.14 Karayanis N M, Nikulski C M, Pytlewsrni L L & labes M M,J

inorg nucl Chem, 34 (1972) 3139.15 Nakamato K, Infrafed and Raman spectra of inorganic and

coordination compounds (John Wiley, New York), 1978,244.16 Ferraro J R, Low frequency vibrations of inorganic and

coordination compounds (plenum Press, New York), 1971,79.17 Cotton F A, Goodgame D M L & Soderberg R H,Inorg Chem, 2

(1963) 1162.18 Nakamato K, Infrared spectra of inorganic and coordination

compounds (John Wiley, New York) 1970, 175.19 Moore L E, Gayhert R B & Bull W E,J inorg nucl Chem, 24(1964)

898.io Dyre G, Hartley J G, & Venanzi L M,J chem Soc(A), (1965) 3091.21 Proctor I M, Hathaway B J & Nicholls P J,J chem Soc (A), (1968)

1678.22 Gray A B, Transition metal chemistry, Vol I, edited by R L Carlin,

(Marcel Dekker, New York) 1965, 239.23 Sacconi L, Transition metal chemistry, Vol. 2,edited by R LCarlin

(Marcel Dekker, New York), 1968, 199.

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l'j rrergn J IVI. oianoert 1.•••r (\£. 1 norruon LJ f\..J mUlf:'C "}lruCl. 1,1'" 11 J

199.20 N••karnoto K, Infrared and Ramall spectra of Inorganic and

,"oordilllllioll compounds (Wiley lruerscience, New York)Ing. p. 199. 228.

21 Hoodson J B. Percy G C & Thornton D A. Transition MI!ItIIell""" 3 (1978) 302.

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