The water-oxidation catalytic activity of [RuII(damp)(bpy) (H2O)]2+ has been determined from manometric and mass spectroscopy studies. Mechanistic details of the catalytic cycle have been studied both experimentally and using DFT and CASSCF/CASPT2 calculations. Characterisation of this Ru(ii) complex and more highly oxidized catalytic intermediates has been accomplished through UV-vis and XAS spectroscopy, as well as through electrochemical techniques. Comparison of XAS spectra with CASSCF/CASPT2 calculations provides insight into the electronic structures of the more highly oxidized species, especially the degree to which oxidation occurs over both atoms of the Ru-O fragment. 18O-labelling experiments indicate that the O-O bond formation step proceeds via a water nucleophilic attack mechanism, and a detailed DFT analysis of the catalytic cycle predicts that step to be rate-determining and to take place for a formal Ru(v)O species. A number of alternative higher energy pathways have also been characterised in order to provide a more complete vision of the whole system. © The Royal Society of Chemistry 2012.
Vigara, L., Ertem, M. Z., Planas, N., Bozoglian, F., Leidel, N., Dau, H., Haumann, M., Gagliardi, L., Cramer, C. J., & Llobet, A. (2012). Experimental and quantum chemical characterization of the water oxidation cycle catalysed by [Ru<sup>II</sup>(damp)(bpy)(H<inf>2</inf>O)]<sup>2+</sup> Chemical Science, 3(8), 2576-2586. https://doi.org/10.1039/c2sc20399e