New Powerful and Oxidatively Rugged Dinuclear Ru Water Oxidation Catalyst: Control of Mechanistic Pathways by Tailored Ligand Design

A new powerful and oxidatively rugged pyrazolate-based water oxidation catalyst of formula {[Ru^II(py-SO₃)₂(H₂O)]₂(μ-Mebbp)}^–, 1(H₂O)₂^–, has been prepared and thoroughly characterized spectroscopically and electrochemically. This new catalyst has been conceived based on a specific ligand tailoring design, so that its performance has been systematically improved. It was also demonstrated how subtle ligand modifications cause a change in the O-O bond formation mechanism, thus revealing the close activation energy barriers associated with each pathway.