First High-Resolution Analysis of the Six Fundamental Bands ν1, ν2, ν3, ν4, ν5, and ν6 of COF35Cl in the 340- to 2000-cm−1 Region

✍ Scribed by A. Perrin; J.-M. Flaud; H. Bürger; G. Pawelke; S. Sander; H. Willner

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 398 KB
• Volume: 209
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2001.8415

✦ Synopsis

Concern about the implication of chlorofluorocarbons (CFCs) in atmospheric ozone depletion has led to numerous measurements of the concentrations of halogen-containing compounds in the stratosphere. Of the various possible oxidation products of CFC's in the stratosphere, carbonyl chlorofluoride (COFCl) may receive special attention. High-resolution atmospheric infrared spectra are potential means of monitoring COFCl. However, there is little information on the spectroscopy of this molecule in the literature. We have therefore recorded spectra of pure 35 Cl-enriched and natural samples of COFCl at ≤0.0033 cm -1 resolution with the BRUKER Fourier transform spectrometer at the University of Wuppertal. We present here the first high-resolution analysis of the six fundamental bands ν 1 (CO stretching mode), ν 2 (C-F stretching mode), ν 3 (C-Cl stretching mode), ν 4 (CFCl bending mode), ν 5 (CFCl rocking mode), and ν 6 (out of plane bending mode) located at 1875.8256, 1095.0646, 764.3876, 501.5941, 408.8099, and 666.5862 cm -1 , respectively, for the COF 35 Cl isotopic species of carbonyl chlorofluoride. The ν 3 , ν 4 , ν 5 , and ν 6 bands which are mainly of A-type, B-type, B-type, and C-type, respectively, appear as unperturbed. On the other hand, both the ν 1 and ν 2 bands have a hybrid character (with both A-and B-type transitions), and the analysis of these two bands was complicated by numerous resonances. Excellent results are obtained for the unperturbed ν 3 -ν 6 bands and for the perturbed ν 2 band, but for the ν 1 band, the resonance scheme of which is more complex, the results of the analysis are slightly less satisfactory.