Artificial photosynthesis via two-electron conversion: Photochemical oxygenation sensitized by ruthenium porphyrins with water as both electron and oxygen atom donor

Abstract

Recent progress in the field of artificial photosynthesis is reviewed. Among various approaches to oxidizing the water molecule, attention has been focused on the two-electron chemical conversion processes mediated by metallo-porphyrins upon visible light irradiation. Photochemical oxygenation reactions such as the epoxidation of alkenes sensitized by ruthenium(II) porphyrins with water as both electron and oxygen atom donor have been found. Ru porphyrin induces highly efficient two-electron oxidation of water with a quantum yield of 60 % to form an epoxide from the alkene with high selectivity. The water molecule serves as both an efficient electron and oxygen atom donor in the reaction, in which the oxygen atom of water is incorporated in a useful product, i.e., epoxide.