Water oxidation by mononuclear ruthenium complexes with TPA-based ligands


The synthesis, characterization, and water oxidation activity of mononuclear ruthenium complexes with tris(2-pyridylmethyl)amine (TPA), tris(6-methyl-2-pyridylmethyl)amine (Me 3TPA), and a new pentadentate ligand N,N-bis(2-pyridinylmethyl)-2,2′-bipyridine-6-methanamine (DPA-Bpy) have been described. The electrochemical properties of these mononuclear Ru complexes have been investigated by both experimental and computational methods. Using Ce IV as oxidant, stoichiometric oxidation of water by [Ru(TPA)(H 2O) 2] 2+ was observed, while Ru(Me 3TPA)(H 2O) 2] 2+ has much less activity for water oxidation. Compared to [Ru(TPA)(H 2O) 2] 2+ and [Ru(Me 3TPA)(H 2O) 2] 2+, [Ru(DPA-Bpy)(H 2O)] 2+ exhibited 20 times higher activity for water oxidation. This study demonstrates a new type of ligand scaffold to support water oxidation by mononuclear Ru complexes. © 2011 American Chemical Society.

Publication Title

Inorganic Chemistry