Fig. 1.
Structures of [Ru(bpy)2(pyESO)]2+ and various photoisomerization pathways. a Molecular structures before and after photoinduced isomerization. Color code: cyan Ru, yellow S, red O, blue N, green C, white H. b Adiabatic photo-isomerization on lowest 3MLCT excited states. c Non-adiabatic photo-isomerization on lowest 3MLCT excited states. d Non-adiabatic photo-isomerization involving 3MLCT and 3MC excited states. Vertical arrows represent photo-absorption and emission processes. Wavy arrows represent non-radiative transitions (conical intersections are not shown for simplicity). Curvy arrows represent adiabatic relaxation paths on potential energy surfaces. Dotted lines represent diabatic states for triplet states. 1GS: S-bonded ground state reactant, 1GO: O-bonded ground state photoproduct, 3MLCTS: S-bonded 3MLCT excited state, 3MLCTO: O-bonded 3MLCT excited state, 3MLCTSO: sideways SO-bonded 3MLCT excited state, 3MCS: S-bonded 3MC excited state, 3MCO: O-bonded 3MC excited state