Spectroscopic studies of oxidized manganese catalase and mu-oxo-bridged dimanganese(III) model complexes: electronic structure of the active site and its relation to catalysis

A study on the catalytically active Mn(III)/Mn(III) binuclear site of oxidized manganese catalase (OxMnCAT) and its interaction with azide is presented. Azide has the same electronic structure as that of hydrogen peroxide. Absorption, MCD and resonance Raman measurements have been undertaken on synthetic complexes having mu-oxo-di-mu-carboxylato-bridged dimanganese(III) units used in modeling the active site of OxMnCAT. Results show that the active site is made up of two ferromagnetically coupled five-coordinate Mn(III) ions linked by a hydroxo bridge.