OXOVANADIUM(IV) COMPLEXES OF BIOINORGANIC AND INDUSTRIAL RELEVANCE: SYNTHESIS AND CHARACTERIZATION OF SOME OXOVANADIUM(IV) COMPLEXES

摘要

Seven new oxovanadium(IV) complexes, formed by the interaction of vanadyl sulfate pentahydrate and the Schiff bases, viz., N-(4'-benzoylidene-3'-methyl-1-phenyl-2'-pyrazolin-5'-one)-p-anisidine (HL~1), N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-m-phenitidine (HL~2), N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-p-toluidine (HL~3), N,N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-0-phenylenediamine (H_2L~4), N.N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-m-phenylenediamine (H_2L~5), N,N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-p-phenylenediamine (H_2L~6) and N,N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-benzidine (H_2L~7) in aqueous-ethanol, are described. The resulting complexes were characterized by elemental analyses, molar conductances, magnetic and decomposition temperature measurements, electron spin resonance, IR and electronic spectral studies. They have the compositions, [VO(L')_2(H_2O)], where HL' = HL~1, HL~2 or HL~3, [VO(L")(H)_2O], where H)_2L" = H_2L~4 or H_2L~5 and [{VO(H_2O)(OH)}_2(L"')], where H_2L"' = H_2L~6 or H_2L~7. The compounds [{VO(H_2O)(OH)}_2(L~6)] and [{VO(H_2O)(OH)}_2(L~7)] were found to show subnormal magnetic moments. Suitable structures have been proposed for these complexes.