VIBRATIONAL EXCHANGE IN THE MANIFOLD OF HIGH-FREQUENCY VIBRATIONS OF THE CH2F2 MOLECULE

Time-resolution Raman scattering spectroscopy has been used to study t he collisional vibrational relaxation of high-frequency 2 nu(8), nu(1) and nu(6) modes in the CH2F2 molecule after their excitation by optic al parametric oscillator pulses. The rate constants of energy exchange between these modes and their relaxation to other modes have been det ermined. The exchange between the stretching C-H vibrations nu(1) and nu(6) have been found to be the fastest. The rate constant of this pro cess has an extremely high value k(32)(nu(6)-->nu(1)) = 1.51 X 10(7) s (-1) Torr(-1) which is higher than the rate of gas-kinetic collisions.