complexes of co(ll). ni(ll). cu(ll). (0.1 m )+ cdrl l). uo~ and v0 o...

Indian Journal of ChemistryVol. 25A. March 1986. pp. 27

INDIAN J. CHEM .• VOL. 25A. MARCH 1986

-+~TI~(P), respectively. These bands suggest anoctahedral stereochemistry for the Cotll) chelate. Thespectrum of the Ni(ll) chelate shows two bands at13,800 and 25.900cm -I assignable to the transitions3A2~-+3Tlg(F) and 3A2g-+3Tlg(P), respectively. Thesebands suggest an octahedral stereochemistry aroundNi(ll) ionl112.

ill the case 01 Cu(lI) chelate a broad-absorptionband ::I iound 12.700 cm - 1 has been observed whichmay be due to the transition 2Eg-+2T2~' It suggestsdistorted octahedral stereochemistry for the Cu(lI)chelate. The VO:" chelate shows two bands at 11,800and 19,985 em I assignable to the transitions d.. -~d,.d, and d.; -~d,2 .2 respectively in the octahedralenvironment 13 of V02 ".

The IR spectrum ofH2BB shows four bands at 1640,1690. 1770 and 3365 em - 1 assignable to J'CN, J'C=0,l'COOH and I'OH modes respectively!". In the spectraof the metal chelaies the bands at J 770 and 3365 em -·1disappeared suggesting deprotonation of OH andCOOH groups on complexation. The IR spectra of themetal chelates and their adducts showed bands in theranges 1620-1610. 510-470 and 400-380cm-1assignable to rC = N. I'M - N and I'M -0 modes,respectivclyl~. All hydrated chelaies show a broadband at 3320 cm . 1 due to I'OH of water moleculespresent. The loss of water molecules at relatively highternper.tture (170-280 C) suggests that they arecoordinated and not lattice held.

Based on the above evidences Co(lll. NiOI). UO~ +and VOl ~ chelatcs and their adducts are assigned anoctahedral stereochemistry ZnOI) and Cdt l lj chelatesand their adducts tetrahedral configuration. andCuI II) chelate and its adduct distorted octahedral

280

geometry (due 10 Jahn-Teller effect 1 ~). Thesestructures may be represented as shown below 0).

ReferencesI Calvin :vi & Wilson K W. J Am chem SOl'. 67 (1945) 2003.~ Bjerrum J. Mete! ammincjormut i{)11 ill aqucous solunnn (P. Haase

& Son. Copenhagen). 1941.3 Mathur R P & Mehta R K, Z phvs Chern. 263 (1982) 974.4 Gupta C P. Mathur R P & Mehta R K. Aria chim Am" Sci HUl1g.

111 (I98~) 19,5 Irving H & Rossetti H S. J ('h(,111 SOL (1953) 3397.6 Irving H & Williams R J P. J ch e:m Soc. (1953) 3192.7 Yatsimirskii K B & Vasil'cv V P. Instubilit v (,OI1.