Knowledge Bank

Excitation energy and isotope dependence of the quantum yield of $S2\to SO$ fluorescence have been utilized for the investigation of the energy dependence of $S2\to S1$ and $S2\to SO$ internal conversion in asulene vapor. It is argued that $S2\to SO$ internal conversion, already important at zero excess energy, becomes the dominant photophysical process with vibrational excitation of the molecule in $S2$.