SYNTHESIS AND CHARACTERIZATION OF SOME COBALT(II), NICKEL(II) AND ZINC(II) COMPLEXES WITH SCHIFF-BASES DERIVED FROM THE REACTION OF 4-HYDROXISALICYLALDEHYDE AND O-VANILLIN WITH 3,5-DI(TERT-BUTYL)-4-HYDROXYANILINE

Two new Schiff bases have been synthesized by the condensation 3,5-di( tert-butyl)-4-hydroxyaniline with 4-hydroxysalicylaldehyde (HL) and (o ) under bar-vanillin (HL'). The complexes of cobalt(II), nickel(II) an d zinc(II) with HL and HL' have been prepared. The analytical data sho w that the metal to ligand ratio in the complexes is 1:2. Molar conduc tance measurements indicate that the complexes are non-electrolytic in nature. The ligands and their complexes are characterized on the basi s of analytical data, conductivity measurements, magnetic moments, inf rared, electronic spectral data and thermal analyses (DTA and TG). The C-13 and H-1 NMR spectra of the Schiff base ligands have been recorde d.