STIMULATED RAMAN-UV OPTICAL DOUBLE-RESONANCE SPECTROSCOPY OF VAN-DER-WAALS COMPLEXES OF BENZENE

Spectroscopic and dynamical studies of the van der Waals complexes of benzene-Ar, benzene-N2 and benzene dimer in the electronically ground state (S0) have been performed by the use of stimulated Raman--UV optical double resonance spectroscopy. The vibrational frequency of mode 1 of the complexes and the decay rate constants of the 11 levels (≈993 cm-1) have been measured. The vibrational frequency shift of mode 1 in S0 upon complex formation were less than 1 cm-1 for all the complexes. On the other hand, the decay rate constant due to intramolecular vibrational redistribution and/or vibrational predissociation showed a drastic change. The decay rate constant of the l1 level of the benzene dimer was 2.4 × 107S-1, while those of the benzene-Ar and benzene-N2 complexes were much smaller than 1 × 106S-1.