QUENCHING OF (1)B(2U) (6(1)) VIBRATIONAL LEVEL OF THE BENZENE MOLECULES AT 300-K BY SEVERAL COLLIDERS

The deexcitation of the 6(1) level of the 1B2u state of the benzene molecule after pulsed laser excitation has been studied. The values obtained for the level lifetime and self-quenching cross section are 89.2 +/- 1.8 ns and 12.6 +/- 1.4 angstrom-2. The quenching cross sections for collisions with Ne, Ar, CH4, NH3, CO, CO2 and O2 have been measured. For the first four colliders no previous data have been reported in the literature. The corresponding results for total quenching cross sections are 0.9 +/- 0.1, 3.4 +/- 0.3, 7.9 +/- 0.6, 22.0 +/- 1.0, 6.7 +/- 0.5, 13.0 +/- 0.8 and 41.0 +/- 1.5 angstrom-2, respectively. The contribution of electronic quenching to these values has been studied.