Electron localization dynamics in the triplet excited state of [Ru(bpy)3]2+ in aqueous solution.

Hybrid DFT/classical molecular dynamics of the long-lived triplet excited state of Ru(bpy)(3) (bpy=2,2'-bipyridine) in aqueous solution is used to investigate the solvent-mediated electron localization and dynamics in the triplet metal-to-ligand charge-transfer (MLCT) state. Our studies reveal a solvent-induced breaking of the coordination symmetry with consequent localization of the photoexcited electron on one or two bipyridine units for the entire length of our simulation, which amounts to several picoseconds. Frequent electronic "hops" between the ligands constituting the pair are observed with a characteristic time of approximately half a picosecond.