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 $\sigma$ for the latter seven molecules decreased as the temperature $T$ increased. For the latter six collision partners $\text{σ∝1\hspace{0.17em}/\hspace{0.17em}T}$ . 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.