Collision Broadening in the Inversion Spectrum of Methyl Chloride at Pressures up to Two Atmospheres

Abstract

SummaryThe power absorption coefficient a of microwaves of wave number v = O· 333 cm-1 by methyl chloride at 33· 7°C has been studied at pressures up to 2 atm, and the results are compared with theoretical predictions. Discrepancies which have previously been attributed to the effect of transitions between low.lying rotational states are shown to be due to three· body collisions. The collision diameter for pressure broadening of the inversion transition in methyl chloride is found to be 8·6 A; this is significantly larger than the figure of 7 . 2 A reported by earlier workers who neglected the effect of three-body collisions.

Pressure-Broadening Effects In Mixtures Of Methyl Chloride And Non-Polar Gases At Microwave Frequencies

“…Measurements in this laboratory of the self-broadening of the inversion spectrum of methyl chloride at pressures up to 2 atm have been reported previously (Burton et al 1964, hereafter referred to as Paper I). This work has now been extended to a study of binary mixtures of methyl chloride with five non-polar gases at pressures up to 4 atm.…”