The second lifetime, and the associated red EADS2 in Figures and for both solvents, are assigned to vibrational cooling (VC) and solvent relaxation (SR) within the triplet manifold. This assignment is supported by the solvent-dependent variations in the second lifetime, measured as 22 ± 4 ps in PBS and 12 ± 2 ps in ACN. The rapid ISC nature and the significant energy gap of 0.86 eV between the T 2 and T 1 states support the premise that the T 1 state is initially populated with a substantial excess of vibrational energy. Finally, the third lifetime (> 3ns) is attributed to the decay of the T 1 state.