Physicochemical studies on some isatin isonicotinoyl hydrazone complexes prepared at PH 10

ABSTRACT

The complexes of Co, Ni, Pd, Cu and Cd of isatin isonicotinoyl hydrazone [HL] were prepared at pH 10 and characterized by elemental analysis and different physical techniques. Magnetic and spectral data suggested octahedral structures for Cu and Ni complexes, but tetrahedral for the Co complex. The dissociation constant pK of the ligand has been determined spectrophotometrically. The DC electrical conductivity of the compressed powder samples was investigated as a function of temperature. The activation energy [delta Eg] was calculated for the ligand and complexes which showed that the ligand has lower delta Eg than the complexes. The magnitudes of delta Eg were correlated with the number of d-electrons of the transition metal ion