Global analysis of 12CH335Cl and 12CH337Cl: Simultaneous fit of the lower five polyads (0-2600 cm-1)

Abstract The global analysis of the infrared spectrum of chloromethane involving the ground state and the 13 vibrational states lying up to 2600 cm −1 is reported. This work incorporates and extends to the fifth polyad, the preliminary study of the lower four polyads published by [J. Mol. Spectrosc. 221 (2003) 199]. More than 20 000 transitions (including numerous hot bands) for each isotopomer 12 CH 3 35 Cl and 12 CH 3 37 Cl have been assigned and fitted with a standard deviation of about 3 × 10 −4  cm −1 close to the experimental precision. A common set of 288 (resp. 303) effective parameters was determined for each isotopomer. Our global model allowed us to reproduce simultaneously and accurately the resonances already encountered in Polyad 3 and the new ones involved in Polyad 5.

[1]  Jean-Paul Champion,et al.  Spherical Top Spectra , 1992 .

[2]  L. Brown,et al.  The infrared spectrum of CH 3 D between 900 and 3200 cm -1 : extended assignment and modeling , 2000 .

[3]  C. Lauro,et al.  Rotational analysis of the ν2 + ν6±1, ν5⊣1 + ν6⊣1, ν5⊣1 + ν6±1, and 2ν3 + ν6±1 interacting infrared bands of methyl chloride , 1980 .

[4]  L. Brown,et al.  Analysis of the CH3D nonad from 2000 to 3300 cm-1 , 2002 .

[5]  Jean-Paul Champion,et al.  Improved Algorithms for the Modeling of Vibrational Polyads of Polyatomic Molecules: Application toTd,Oh, andC3vMolecules , 1997 .

[6]  Jean-Paul Champion,et al.  The MIRS computer package for modeling the rovibrational spectra of polyatomic molecules , 2003 .

[7]  Laurence S. Rothman,et al.  The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001 , 2003 .

[8]  Jean-Paul Champion,et al.  Global analysis of chloromethane: determinability of ground state constants , 2004, Symposium on High-Resolution Molecular Spectroscopy.

[9]  J. Champion.  Développement complet de l'hamiltonien de vibration–rotation adapté à l'étude des interactions dans les molécules toupies sphériques. Application aux bandes ν2 et ν4 de 12CH4 , 1977 .

[10]  A. Nikitin,et al.  New measurements and global analysis of chloromethane in the region from 0 to 1800 cm−1 , 2003 .

[11]  J. Demaison,et al.  Infrared and millimeter-wave studies of in the ground, 31, and 61 states ☆ , 2003 .

[12]  A. Weber,et al.  Spectroscopy of the Earth's Atmosphere and Interstellar Medium , 1992 .

[13]  A. Nikitin.  Méthode des opérateurs tensoriels irréductibles en spectroscopie moléculaire : développement d'algorithmes et application à l'étude du spectre de la molécule CH3D , 1996 .

[14]  A. Nikitin,et al.  New ground state constants of 12CH335Cl and 12CH337Cl from global polyad analysis , 2005 .