METHYL-CHLORIDE NU(5) REGION LINESHAPE PARAMETERS AND ROTATIONAL-CONSTANTS FOR THE NU(2), NU(5), AND 2-NU(3) VIBRATIONAL BANDS

Fourier spectra of methyl chloride have been obtained at ambient labor atory temperature under self-broadening conditions. Five thousand two hundred and sixty rovibrational transitions of the (nu(2), nu(5), 2 nu (3))-vibrational-band tried have been assigned, and new ground and exc ited state rotational constants for (CH3Cl)-Cl-35 and (CH3Cl)-Cl-27 ha ve been determined. The nu(5) and nu(2) vibrational-band intensities a re 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 nu(5) band of (CH3Cl)-Cl-35 and (CH3Cl)-Cl-37 at 29 6 K. The self-broadening coefficients peak broadly close to the maximu m in the Boltzmann rotational population; no specific trends of the br oadening coefficients are observed with the rotational quantum number K. With the exception of the (R)Q(J, 0) branch, the 1260-1650 cm(-1) s pectral region can be well modeled by the superposition of overlapping Voigt line profiles. To adequately model the densely packed (R)Q(J, 0 ) branch, however, we included collisional line mixing with A(+) to A( -) in addition to A(-) to A(-) and A(+) to A(+) \Delta J\ greater than or equal to 1, Delta K = 0 collisional transitions allowed. (C) 1998 Academic Press.