STRUCTURAL ELUCIDATION OF O-VANILLIN ISONICOTINOYL HYDRAZONE AND ITS METAL-COMPLEXES

A new series of complexes with the tridentate dibasic Schiff base liga nd o-vanillin isonicotinoyl hydrazone(o-VINH) were prepared and charac terized by i.r., H-1 n.m.r. and electronic spectral studies, magnetic susceptibility measurements and t.g.a. The disappearance of low field signals due to OH, NH protons at 10.23 and 9.31 p.p.m. and downfield s hift of the -CH=N proton signal at 8.17 p.p.m. in the n.m.r. spectrum confirms the involvement of these groups in coordination. Both t.g.a. and i.r. spectral data show evidence for one molecule of coordinated H 2O. These results taken in conjunction with electronic spectral data a llow assignation of tetrahedral geometry for manganese(II), nickel(II) and palladium(II) complexes but a square planar configuration to coba lt(II), copper(II) amd zinc(II) complexes.