SYNTHESIS, POTENTIOMETRIC AND ANTIMICROBIAL STUDIES ON METAL COMPLEXES OF THIAZOLE SCHIFF BASE

The synthesis of the Schiff base ligand salicylidene-3-phenyl-2-aminothiazole (LH2)and their Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Cd(II) metal complexes have been reported. The structure of ligand and their complexes was investigated using elemental analysis, IR, UV-Vis, 1H NMR, magnetic susceptibility and conductance measurements. Protonation constants of Schiff base and stability constants of their binary metal complexes have been determined potentiometrically in 50% DMSO–water media at 25°C and ionic strength 0.10 M sodium perchlorate. Antimicrobial activity of the ligand and metal complexes were tested using the disc diffusion method and the strains Bacillus megaterium and Candida tropicalis. The stability constants were found to follow the order: Cr(III) < Mn(II) < Co(II) < Ni(II) < Cu(II) > Fe(III).