Synthesis, Characterization and Anti-oxidative Activity of Cobalt(II), Nickel(II) and Iron(II) Schiff Base Complexes

Abstract

Six complexes, M(HL)₂ · nH₂O (M=Co, Ni and Fe; n=4) with two ligands, 2-carboxy-benzaldehydebenzoylhydrazone (H₂L¹) and 2-carboxybenzaldehyde-(4′-methoxy)benzoylhydrazone (H₂L²), have been synthesized and characterized on the basis of elemental analyses, molar conductivities, i.r. spectra and thermal analyses. In addition, the suppression ratio for O ^-₂ (a) and the suppression ratio for OH^· (b) were determined with a 72 spectrophotometer. The 50% inhibition [IC₅₀ (a) and IC₅₀ (b)] of the complexes were studied. This study demonstrated that the complexes have activity in the suppression of O ^-₂ (a) and OH^· (b). In general, the antioxidative activities increased as the concentration of these complexes increased up to a selected extent. The complexes exhibit more effective antioxidants than the ligands and the series of the ligand (H₂L²) are better than the series of the ligand (H₂L¹) do.