Methyl Chloride nu5 Region Lineshape Parameters and Rotational Constants for the nu2, nu5, and 2nu3 Vibrational Bands.

Fourier spectra of methyl chloride have been obtained at ambient laboratory temperature under self-broadening conditions. Five thousand two hundred and sixty rovibrational transitions of the (nu2, nu5, 2nu3)-vibrational-band triad have been assigned, and new ground and excited state rotational constants for CH335Cl and CH327Cl have been determined. The nu5 and nu2 vibrational-band intensities are determined to be, respectively, 42(1.2) and 31.7(0.9) cm-2 atm-1. Self-broadening coefficients of individual rovibrational lines are determined for the nu5 band of CH335Cl and CH337Cl at 296 K. The self-broadening coefficients peak broadly close to the maximum in the Boltzmann rotational population; no specific trends of the broadening coefficients are observed with the rotational quantum number K. With the exception of the RQ(J, 0) branch, the 1260-1650 cm-1 spectral region can be well modeled by the superposition of overlapping Voigt line profiles. To adequately model the densely packed RQ(J, 0) branch, however, we included collisional line mixing with A+ to A- in addition to A- to A- and A+ to A+ |DeltaJ| >/= 1, DeltaK = 0 collisional transitions allowed. Copyright 1998 Academic Press.