Intersymmetry and Coriolis-assisted intermode vibrational energy transfers in CD3Cl from infrared double-resonance measurements

The time-resolved infrared (IR) double-resonance method has been applied to the study of collision-induced vibrational energy transfers in CD3Cl. The fast energy transfer between the Coriolis-coupled levels of the v2=1 and v5=1 vibrational states of CD3Cl was investigated both in the pure gas and in mixtures with argon yielding rate constants, respectively, equal to (1.18±0.08)107 and (2.12±0.78)106 s−1 Torr−1. This fast intermode transfer is found to occur only between rovibrational levels of the same symmetry type. The V–V transfer between the A and E symmetry levels has also been observed, as well as the V–V transfer between the two isotopic species CD335Cl and CD337Cl. The measured rate constants for these processes are very close and equal to (6.1±0.4)105 s−1 Torr−1. The rate constant for the vibrational thermalization was also determined and found to be (2.5±0.5)103 s−1 Torr−1, in agreement with previous studies.