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 {[RuII(py-SO3)2(H 2O)]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. © 2013 American Chemical Society.