Electrocatalytic water oxidation by a molecular cobalt complex through a high valent cobalt oxo intermediate

Abstract

Biuret-modified tetraamidomacrocyclic cobalt complex [Co^III-bTAML]⁻ is shown to catalyze electrochemical water oxidation at basic pH leading to the formation of O₂. Electrochemical and spectroscopic studies indicate a high valent cobalt oxo intermediate isoelectronic to Co^V(O) as the active oxidant. The kinetic isotope effect of 8.63 indicates an atom proton transfer mechanism.