Self-Organization of a Binuclear Ruthenium Complex to Tetra- and Octanuclear Catalysts for Water Oxidation for “Artificial Photosynthesis”

Abstract

The kinetics and mechanism of the action of tetra- and octanuclear ruthenium catalysts for water oxidation with Ce(IV) compounds in “artificial photosynthesis” have been studied. These catalysts are formed from a complex K₄[Ru₂(SO₄)₂(μ-SO₄)₂(μ-O)₂] · 2H₂O in an acidic medium via its self-organization. A tetranuclear adamantane-like cluster Ru₄O₆ is obtained during the dimerization of a binuclear complex and catalyzes the four-electron water oxidation to an oxygen molecule. An octanuclear cluster Ru₈O₁₂ is formed during the tetramerization of a binuclear complex and catalyzes the eight-electron water oxidation to an oxozone molecule O₄, which readily splits to two oxygen molecules.