Unique Reactivity of Peroxide Ion Trapped by Binuclear Iron(III) Complex

Metalloproteins that catalyse the incorporation of oxygen atom derived from dioxygen into organc substrates usually contain either iron or copper. Our understanding of the mechanism involved in the reaction of the iron-containing heme oxygenases has been substantially advanced by the characterization of high-valent iron porphyrin oxo-complexes capable of epoxidation or hydroxylation of organic substrates [1—4]. In the case of copper enzymes e.g., tyrosinase [5] or dopamin-/?-hydroxylase [6], our understanding is much limited, and no suitable model has been reported for tyrosinase reaction. In the preceding paper, Nishida etal. [7] showed that the binuclear iron(III) complex with//-alkoxo bridge, Fe2(L)(N03)5, reacts with H 2 0 2 to yield a blue species 1, where H(L) denotes l,3-bis[N,N-bis(2-benzimidazolylmethyl)aminomethyl]-2-hydroxypropane.