SYNTHESIS, CRYSTAL-STRUCTURE AND SUPEROXIDE-DISMUTASE ACTIVITY OF A 5-CO-ORDINATED MANGANESE(II) COMPLEX

A five-co-ordinate manganese(II) complex [Mn(ntb)(Hsal)][ClO4], where ntb is tris(benzimidazol-2-ylmethyl)-amine and Hsal(-) is the anion of salicyclic acid (H(2)sal), has been prepared and characterized by X-r ay crystallography. The manganese adopts a distorted trigonal-bipyrami dal co-ordination geometry with a N4O ligand donor set and bears struc tural similarities to the active site of manganese superoxide dismutas e. The electrochemical properties of the complex were studied in MeCN by cyclic voltammetry. The complex can catalyse the dismutation of sup eroxide (O-2(-)) effectively in the riboflavin-methionine-nitro blue t etrazolium assay.