STUDIES ON THE SYNTHESIS AND MAGNETISM OF BINUCLEAR OXOVANADIUM(II) COMPLEXES OF SOME ISONICOTINOYL HYDRAZONES

Three novel binuclear oxovanadium(II) complexes have been synthesized, namely [(VO)2(H2pfhmp)(mu-CNO)]SO43H2O (1), [(VO)(AcAcNH)]2H2O (2) and [(VO)(SIH)]2H2O (3), where (H2PfhMP)1-, (AcAcNH)2- and (SIH)2- denote deprotonated anions of N,N'-diisonicotinoyl-2-hydroxy-5-methylisophthalaldehyde dihydrazone, acetylacetone-isonicotinoyl hydrazone and salicylaldehyde-isonicotinoyl hydrazone respectively. CNO is the exogenous bridging group of complex (1), these complexes were characterized by IR, elemental analysis and conductivity measurements. The determination of variable-temperature magnetic susceptibilities shows that there is antiferro-magnetic spin-exchange interaction between two oxovanadium(II) ions within each molecule.