Relaxation in molecular infrared absorption. 3. Dichlorofluoromethane at several wavenumbers. Effect of rotational energy

Abstract

Relaxation to photophysical steady state during infrared absorption was measured at four different wavenumbers, distributed over the C-F stretching band so as to vary the average rotational energy of the absorbing molecules between 2.4 and 7.8 kJ/mol. Pressure of CHC12F ranged from 1.5-47 Torr. Mean vibrational energy ranged from 3.37 to 20 kJ/mol. The relaxation mechanism is collisional and, as in the case of CHC1F2, consists of parallel R-R' and resonant V-V exchange. The rate constants are practically independent of the rotational energy.