Rotational energy transfer in CH3F: The ΔJ=n, ΔK=0 processes

Abstract

We report the measurement of the rates o ΔJ=n, ΔK=0(‖n‖≤10) processes for CH3F–CH3F collisions at 300 K. The data are derived from a time-resolved millimeter/submillimeter-infrared double resonance investigation of both the 12CH3F and the 13CH3F isotopic species. The rates were obtained via a nonlinear least-squares analysis of the data using a numerical simulation of rotational energy transfer in methyl fluoride. These rates are shown to be quantifiable in terms of the scaling law of infinite order sudden collision theory and the statistical power gap law. As a result, the numerous ΔJ=n, ΔK=0(‖n‖>1) rates can be understood in terms of only two parameters, independent of isotopic species. Using these results and the results of our earlier studies of K-changing processes, we discuss how rotational energy transfer in the CH3F system in general can be described in terms of a small number of collisional processes and parameters.