Application of 3-Quinolinoyl Picket Porphyrins to the Electroreduction of Dioxygen to Water: Mimicking the Active Site of Cytochromec Oxidase

Functional analogues of the so-called Fea3–CuB active site of cytochrome c oxidase were synthesized to elucidate the mechanism of the reduction of O2 to H2O. The role of each individual structural component, especially the CuB center, for catalytic activity was investigated. These quinolinoyl picket iron porphyrins (see picture) were shown to be efficient catalysts for the 4 e− reduction of dioxygen to water with or without a Cu ion in their distal site, clearly demonstrating that the Cu center is not essential for the catalytic activity.