Vibrational predissociation in weakly-bound clusters: A dispersed fluorescence study of toluene rare-gas complexes

The vibrational predissociation (VP) dynamics of toluene–Ar and toluene–Ne complexes have been investigated using single vibronic level fluorescence spectroscopy. For several levels, comparison of the dispersed fluorescence spectra with those from monomer levels permits the identification of the final monomer vibrational level. Pumping of the low-lying S1 13 0 1 / 24 0 1 25 0 1 ¯ or 37 0 1 ¯ transitions in toluene–Ar, for example, gives rise to efficient VP leaving the resulting toluene monomer in its vibrationless S1 state. By contrast, in the case of toluene–Ne, VP following 37 1 ¯ level pumping leaves the toluene molecule in an excited 161 level which is optically inaccessible from the ground state.