Study of Proton Coupled Electron Transfer in a Biomimetic Dimanganese Water Oxidation Catalyst with Terminal Water Ligands.

ABSTRACT: The oxomanganese complex [H(2)O(terpy)Mn(III)(μ-O)(2)Mn(IV)(terpy)H(2)O](3+) (1, terpy = 2,2':6-2″-terpyridine) is a biomimetic model of the oxygen evolving complex of photosystem II with terminal water ligands. When bound to TiO(2) surfaces, 1 is activated by primary oxidants (e.g., Ce(4+)(aq), or oxone in acetate buffers) to catalyze the oxidation of water yielding O(2) evolution [G. Li et al. Energy Environ. Sci. 2, 230-238 (2009)]. The activation is thought to involve oxidation of the inorganic core [Mn(III)(μ-O)(2)Mn(IV)](3+) to generate the [Mn(IV)(μ-O)(2)Mn(IV)](4+) state 1(ox) first and then the highly reactive Mn oxyl species Mn(IV)O(•) through proton coupled electron transfer (PCET). Here, we investigate the step 1 → 1(ox) as compared to the analogous conversion in an oxomanganes

SUBMITTER: Wang T 

PROVIDER: S-EPMC2935188 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature