Excited-state dynamics of (SO2)m clusters

A study of the excited-state dynamics of (SO2)m clusters following excitation by ultrafast laser pulses in the range of 4.5 eV (coupled 1A2, 1B1 states) and 9 eV (F band) is presented. The findings for the coupled 1A2 and 1B1 states are in good agreement with published computational work on the properties of these coupled states. A mechanism involving charge transfer to solvent is put forward as the source of the excited-state dynamics that follow the excitation of the SO2 F band within (SO2)m+1 clusters with m > 1. The proposed CTTS mechanism is supported by calculations of the energetics of the process and the observed trends in the excited-state lifetimes that correlate very well with the calculated energies.