Methyl Chloride ν5Region Lineshape Parameters and Rotational Constants for the ν2, ν5, and 2ν3Vibrational Bands

✍ Scribed by C. Chackerian Jr.; L.R. Brown; N. Lacome; G. Tarrago

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 424 KB
• Volume: 191
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1998.7591

✦ Synopsis

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 ( 2 , 5 , 2 3 )-vibrational-band triad have been assigned, and new ground and excited state rotational constants for CH 3 35 Cl and CH 3 27 Cl have been determined. The 5 and 2 vibrational-band intensities are determined to be, respectively, 42(1.2) and 31.7(0.9) cm Ϫ2 atm Ϫ1 . Self-broadening coefficients of individual rovibrational lines are determined for the 5 band of CH 3 35 Cl and CH 3 37 Cl 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 R Q(J, 0) branch, the 1260 -1650 cm Ϫ1 spectral 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 ϩ to A Ϫ in addition to A Ϫ to A Ϫ and A ϩ to A ϩ |⌬J| Ն 1, ⌬K ϭ 0 collisional transitions allowed.