Copper-dioxygen chemistry and modeling the Fe-Cu center in cytochrome c oxidase

Abstract

The copper(I) complex [(TMPA)Cu(RCN)]+(1) binds O2forming [{(TMPA)Cu}2-(O2)]2+(2), with trans-μ-1, 2 peroxo-coordination. Ligands with quinolyl groups substituting for the pyridyl donors in TMPA cause dramatic changes in the course of reaction, in one case stabilizing a Cu/o21:1 adduct [(BQPA)Cu(O2)]+(6). The kinetics/thermodynamics are compared. Reaction of 1 with (F8-TPP)Fe(II)pip2(8) and O2 yields the| μ-oxo species [(Fg-TPP)FeIII-O-CuII(TMPA)]+(9); this reversibly protonates giving μ-hydroxo bridged [(F8-TPP)Fe-(OH)-Cu(TMPA)]2+(12). The novel NMR properties of 9 are described. These complexes are discussed in terms of their model 02-chemistry in hemocyanins or cytochrome c oxidase. © 1995 IUPAC