A molecular ruthenium catalyst with water-oxidation activity comparable to that of photosystem II.

Across chemical disciplines, an interest in developing artificial water splitting to O(2) and H(2), driven by sunlight, has been motivated by the need for practical and environmentally friendly power generation without the consumption of fossil fuels. The central issue in light-driven water splitting is the efficiency of the water oxidation, which in the best-known catalysts falls short of the desired level by approximately two orders of magnitude. Here, we show that it is possible to close that 'two orders of magnitude' gap with a rationally designed molecular catalyst [Ru(bda)(isoq)(2)] (H(2)bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; isoq = isoquinoline). This speeds up the water oxidation to an unprecedentedly high reaction rate with a turnover frequency of >300 s(-1). This value is, for the first time, moderately comparable with the reaction rate of 100-400 s(-1) of the oxygen-evolving complex of photosystem II in vivo.

[1]  James D. Blakemore,et al.  Highly active and robust Cp* iridium complexes for catalytic water oxidation. , 2009, Journal of the American Chemical Society.

[2]  L. Spiccia,et al.  Development of Bioinspired Mn4O4—Cubane Water Oxidation Catalysts: Lessons from Photosynthesis , 2010 .

[3]  Keisuke Kawakami,et al.  Crystal structure of oxygen-evolving photosystem II at a resolution of 1.9 Å , 2011, Nature.

[4]  Licheng Sun,et al.  Isolated seven-coordinate Ru(IV) dimer complex with [HOHOH](-) bridging ligand as an intermediate for catalytic water oxidation. , 2009, Journal of the American Chemical Society.

[5]  Licheng Sun,et al.  Evolution of O2 in a seven-coordinate Ru(IV) dimer complex with a [HOHOH]- bridge: a computational study. , 2010, Angewandte Chemie.

[6]  M. Costas,et al.  Efficient water oxidation catalysts based on readily available iron coordination complexes. , 2011, Nature chemistry.

[7]  Stenbjörn Styring,et al.  Towards artificial photosynthesis: ruthenium–manganese chemistry for energy production , 2001 .

[8]  T. Moore,et al.  Solar fuels via artificial photosynthesis. , 2009, Accounts of chemical research.

[9]  E. Schröder,et al.  Stacking interactions and the twist of DNA. , 2008, Journal of the American Chemical Society.

[10]  S. Bernhard,et al.  Fast water oxidation using iron. , 2010, Journal of the American Chemical Society.

[11]  Ralph L. House,et al.  Chemical approaches to artificial photosynthesis , 2012, Proceedings of the National Academy of Sciences.

[12]  A. Llobet,et al.  Oxygen—Oxygen Bond Formation Pathways Promoted by Ruthenium Complexes , 2010 .

[13]  Licheng Sun,et al.  Chemical and light-driven oxidation of water catalyzed by an efficient dinuclear ruthenium complex. , 2010, Angewandte Chemie.

[14]  V. Pecoraro,et al.  Reflections on Small Molecule Manganese Models that Seek to Mimic Photosynthetic Water Oxidation Chemistry. , 2008, Coordination chemistry reviews.

[15]  Qiushi Yin,et al.  A Fast Soluble Carbon-Free Molecular Water Oxidation Catalyst Based on Abundant Metals , 2010, Science.

[16]  M. K. Brennaman,et al.  Chemical approaches to artificial photosynthesis. 2. , 2005, Inorganic chemistry.

[17]  Dirk C. Mattfeld,et al.  A Computational Study , 1996 .

[18]  Antoni Llobet,et al.  Molecular catalysts that oxidize water to dioxygen. , 2009, Angewandte Chemie.

[19]  C. Berlinguette,et al.  Electrochemical evidence for catalytic water oxidation mediated by a high-valent cobalt complex. , 2011, Chemical communications.

[20]  Christian Limberg,et al.  The Mechanism of Water Oxidation: From Electrolysis via Homogeneous to Biological Catalysis , 2010 .

[21]  M. Albrecht,et al.  Water oxidation catalyzed by strong carbene-type donor-ligand complexes of iridium. , 2010, Angewandte Chemie.

[22]  C. Cramer,et al.  The Ru-Hbpp water oxidation catalyst. , 2009, Journal of the American Chemical Society.

[23]  Martin Egli,et al.  Water-nucleobase "stacking": H-pi and lone pair-pi interactions in the atomic resolution crystal structure of an RNA pseudoknot. , 2003, Journal of the American Chemical Society.

[24]  Susan W. Gersten,et al.  Catalytic oxidation of water by an oxo-bridged ruthenium dimer , 1982 .

[25]  D. Nocera,et al.  Electocatalytic water oxidation by cobalt(III) hangman β-octafluoro corroles. , 2011, Journal of the American Chemical Society.

[26]  S. Bernhard,et al.  Cyclometalated iridium(III) Aquo complexes: efficient and tunable catalysts for the homogeneous oxidation of water. , 2008, Journal of the American Chemical Society.

[27]  L. Spiccia,et al.  Development of bioinspired Mn4O4-cubane water oxidation catalysts: lessons from photosynthesis. , 2009, Accounts of chemical research.