Preparation, Characterization, and Catalytic Studies of Iron and Cobalt Complexes Supported by ONNO − Tetradentate Schiff-Base Ligands

Abstract

The free and polymer anchored complexes of iron and cobalt [3-MHBdMBn-M and P-3-MHBdMBn-M], supported by ONNO-tetradentate Schiff-base ligands are prepared by the reactions of metal solution with one molar equivalent of unsupported 3-MHBdMBn (N, N'-bis (2-hydroxy-3-methylbenzaldehyde) 4-Methylbenzene-1,2-diamine) or polymer supported (P-3-MHBdMBn) Schiff-base ligands in methanol. The structural study reveals that iron(III) complex of 3-MHBdMBn Schiff base is octahedral in geometry, whereas, cobalt(II) ions complexes is square planar. Complexation of metal ions increased the thermal stability of 3-MHBdMBn Schiff base. The catalytic activities of metal complexes towards the oxidation of phenol are investigated in the presence of hydrogen peroxide. Experimental results indicate that the reactivity of P-3-MHBdMBn-M is dramatically affected by the polymer support over 3-MHBdMBn-M and iron complexes have greater activity than the cobalt analogue.