Reactivity of dioxygen-copper systems

The mechanism by which copper complexes bind and activate dioxygen was analyzed. The kinetic and thermodynamic information was obtained through cryogenic stopped-flow studies of the oxygenation of Cu(I) compounds. It was shown that protonation or acylation of peroxo copper species appears to enhance their O-atom transfer reactivity. It was concluded that O-O homolysis or heterolysis in CuOOH(R) complexes is energetically disfavored because of thermodynamic instability of the resulting Cu(III/IV)-oxo species.