Figure 6.
Excited-state dynamics of [Ru(II)(bpy)2(S–Sbpy)]2+ (bpy = 2,2′-bipyridine, S–Sbpy = [1,2]dithiino[4,3-b:5,6-b′]dipyridine). (a) Time evolution of electronic state populations colored according to the charge transfer (CT) character. (b) Charge transfer mechanism obtained from a surface hopping study carried out on 161-dimensional potential energy surfaces based on TDDFT linear vibronic coupling models. An excitation at a high-energy absorption bands that is dominated by metal-to-ligand charge transfer (MLCT) excitations to the bpy ligands [green/turquoise contributions in (a), starting at the left-hand side] is after 250 fs very similar to the results obtained when exciting into the lowest-energy absorption band corresponding to states where the S–Sbpy ligand [yellow/orange contributions in (a), starting at the right-hand side] is predominant. This means that in less than 200 fs excitations are located in the disulfide ligand, regardless of the excitation wavelength. Reproduced from ref (129). Copyright 2021 American Chemical Society.