The Far Infrared Spectrum of HOCl: Line Positions and Intensities

✍ Scribed by J.-M. Flaud; M. Birk; G. Wagner; J. Orphal; S. Klee; W.J. Lafferty

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 161 KB
• Volume: 191
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1998.7653

✦ Synopsis

The far infrared spectrum of HOCl has been recorded at high resolution between 20 and 360 cm Ϫ1 by means of Fourier transform spectroscopy, and it was possible to observe pure rotation lines involving rotational levels with high K a quantum numbers (up to K a ϭ 9). These lines combined with microwave and tunable far infrared data available in the literature were least squares fitted using a Watson-type Hamiltonian. The fitting leads to precise sets of rotational and centrifugal distortion constants for the ground states of both isotopomers HO 35 Cl and HO 37 Cl. Also relative line intensities were measured and their fitting allowed the determination of rotational corrections to the b-component of the permanent transition moment. Finally, to get Hamiltonian constants consistent with the newly determined ground state constants for the (100), ( 010), ( 001) vibrational states, available data concerning the 1 , 2 , and 3 bands were refitted. Three interesting points are to be stressed. For the (001) state, we were able to complete the existing data with rotation lines observed in our spectra up to rather high K a values (K a ϭ 7). For HO 35 Cl, we were able to show that some ( 010) and ( 100) levels are perturbed by levels of the ( 002) and ( 030) states, respectively, through Coriolis-type interactions. This allows the determination of the band centers of these two dark states.