Near-Resonant Vibration→Vibration Energy Transfer: CO2(υ3 = 1) + M → CO2(υ1 = 1) + M* + ΔE

Abstract

The laser-excited vibrational fluorescence technique has been used to determine the rate constants for deactivation of the asymmetric stretching vibration of CO2 in collisions with CO2, CH4, C2H4, CH3F, CH3Cl, CH3Br, CH3I, BCl3, and SF6. Rates were determined as a function of temperature in the range 300–800°K. The large deactivation cross sections σ for the latter seven molecules decreased as the temperature T increased. For the latter six collision partners σ∝1 / T. This result is interpreted as a near-resonant vibrational energy transfer process in which three vibrational quantum numbers change as the vibrational energy is shared between the collision partners.