Basic approach to development of environment-friendly oxidation catalyst materials. Mononuclear hydroperoxo copper(II) complexes

In this review, basic studies on the binding and activation of dioxygen species by copper complexes with originally designed ligands are described as the initial step for development of environment-friendly oxidation catalyst. In order to examine the stability/reactivity of such a mononuclear copper(II) complex, some copper complexes with hydroperoxide ion have been constructed using the ligands that have been prepared on the basis of the active center structures of metalloenzymes, and the effects of (i) hydrogen bond, (ii) hydrophobic sphere, (iii) coordination structure around metal, and (iv) coordinating atoms have been investigated systematically, from the point of view of synthetic, spectroscopic, structural, kinetic, and theoretical chemistries. It has also been found out that the decomposition rate constants and the O-O bond strengths of hydroperoxo copper(II) complexes are strongly correlated.