Subpicosecond Dynamics of Metal-to-Ligand Charge-Transfer Excited States in Solvated [Ru(bpy)3]2+ Complexes

Subpicosecond dynamics of metal-to-ligand charge-transfer (MLCT) excited states of [Ru(bpy)(3)](2+) (bpy = 2,2'-bipyridine) in solution is investigated through a mixed time-dependent quantum-classical dynamics computational method that can be applied to a wide class of solvated transition-metal complexes. Both solute and solvent systems are treated at the same atomistic quantum dynamics level of theory. We study the processes of induced polarization, depolarization, and interligand electron-transfer (ILET) kinetics within the complex as well as solvation dynamics effects on the MLCT state relaxation. Liquid acetonitrile and water are considered as solvent media. It is found that the characteristic time scale for ILET is in the range of hundreds of femtoseconds for both solvent cases and polarization relaxation is even faster.