Synthesis and structural characterization of a new high-valent bis(oxo)-bridged manganese(IV) complex and its catechol oxidase activity

The work in this report presents the synthesis, structural and spectroscopic characterization of a new type of high-valent bis(oxo)-bridged dimanganese(IV) complex 1 supported by a pyridine and phenol based tetradentate flexible N3O donor HL ligand (where HL = 2-benzy1-6-((bis(pyridin-2-ylmethyl) amino)methyl)-4-chlorophenol). Complex 1 possess unique Mn-2(mu-O)(2) core with short Mn...Mn distances (2.65 angstrom) and Mn-O distance (1.80 angstrom). This dinuclear manganese(IV) complex show excellent catecholase-like activity for the aerobic oxidation of 3,5-di-tert-butylcatechol to the corresponding o-quinone in acetonitrile at 25 degrees C. Kinetic measurements suggest that the rate of catechol oxidation follows saturation kinetics with respect to the substrate and first order kinetics with respect to the catalyst. (C) 2017 Elsevier B.V. All rights reserved.