Supramolecular water oxidation with Ru-bda-based catalysts.

Extremely slow and extremely fast new water oxidation catalysts based on the Ru-bda (bda=2,2'-bipyridine-6,6'-dicarboxylate) systems are reported with turnover frequencies in the range of 1 and 900 cycles s(-1) , respectively. Detailed analyses of the main factors involved in the water oxidation reaction have been carried out and are based on a combination of reactivity tests, electrochemical experiments, and DFT calculations. These analyses give a convergent interpretation that generates a solid understanding of the main factors involved in the water oxidation reaction, which in turn allows the design of catalysts with very low energy barriers in all the steps involved in the water oxidation catalytic cycle. We show that for this type of system π-stacking interactions are the key factors that influence reactivity and by adequately controlling them we can generate exceptionally fast water oxidation catalysts.

[1]  A. Llobet,et al.  New powerful and oxidatively rugged dinuclear Ru water oxidation catalyst: control of mechanistic pathways by tailored ligand design. , 2014, Journal of the American Chemical Society.

[2]  C. Cramer,et al.  A self-improved water-oxidation catalyst: is one site really enough? , 2014, Angewandte Chemie.

[3]  X. Zou,et al.  Insights into Ru-based molecular water oxidation catalysts: electronic and noncovalent-interaction effects on their catalytic activities. , 2013, Inorganic chemistry.

[4]  A. Llobet,et al.  New dinuclear ruthenium complexes: structure and oxidative catalysis. , 2013, Inorganic chemistry.

[5]  Lei Wang,et al.  Visible light driven water splitting in a molecular device with unprecedentedly high photocurrent density. , 2013, Journal of the American Chemical Society.

[6]  B. Iverson,et al.  Rethinking the term “pi-stacking” , 2012 .

[7]  Antoni Llobet,et al.  A molecular ruthenium catalyst with water-oxidation activity comparable to that of photosystem II. , 2012, Nature chemistry.

[8]  A. Llobet,et al.  Substitution reactions in dinuclear Ru-Hbpp complexes: an evaluation of through-space interactions. , 2012, Inorganic chemistry.

[9]  Biaobiao Zhang,et al.  Highly efficient oxidation of water by a molecular catalyst immobilized on carbon nanotubes. , 2011, Angewandte Chemie.

[10]  T. Mallouk,et al.  Photoinduced Electron Transfer in Covalently Linked Ruthenium Tris(bipyridyl)-Viologen Molecules: Observation of Back Electron Transfer in the Marcus Inverted Region , 1992 .

[11]  G. Wilkinson,et al.  Dichlorotetrakis(dimethyl sulphoxide)ruthenium(II) and its use as a source material for some new ruthenium(II) complexes , 1973 .