Manganese(II) Complex of an oxygen–Nitrogen Donor Schiff base ligand showing efficient Catechol Oxidase Activity: Synthesis, Spectroscopic and Kinetic Study
Tridentate O,N,O donor Schiff base ligand (E)-1-(2-hydroxybenzylidene)semicarbazide (H2L1) and its Mn(II) complex have been synthesized. Both the ligand and the complex have been characterized by analytical and spectroscopic techniques. X-ray crystal structure determination of the Mn(II) complex shows that Mn(II) atom is in a distorted octahedral environment and there are two crystallographically different manganese atoms in the unit cell. The Mn(II) complex shows very high catalytic activity for catechol oxidation (kcat =3.10×106 h−1, kcat/KM= 3.25×108h−1M−1), which is the highest catalytic efficiency for catechol oxidation by a manganese complex reported in the literature . The probable mechanism of the catalytic reaction is explored using ESI-MS and EPR spectroscopy.