Abstract
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.
Original language | English (US) |
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Pages (from-to) | 2576-2586 |
Number of pages | 11 |
Journal | Chemical Science |
Volume | 3 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2012 |