The ν1+ ν3and 2ν1+ ν3Band Systems of SO2: Line Positions and Intensities

✍ Scribed by W.J. Lafferty; A.S. Pine; Georg Hilpert; R.L. Sams; J.-M. Flaud

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 214 KB
• Volume: 176
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.0088

✦ Synopsis

The room temperature infrared spectra of the a-type n 1 / n 3 , n 1 / n 2 / n 3 0 n 2 , and 2n 1 / n 3 bands of 32 SO 2 and the n 1 / n 3 band of 34 SO 2 have been recorded using a difference-frequency laser spectrometer and completely analyzed. It is possible to reproduce the rotational energy levels for the (201) and (111) vibrational states using a single Watsontype Hamiltonian, but it is necessary to consider the weak Fermi-type interaction coupling the rotational energy levels of the ( 101) state with those of the (021) vibrational state in order to fit the energy levels of ( 101). The band centers, n 0 (101), n 0 (111), and n 0 (201), were determined to be 2499.87003 (20), 3010.31730(20), and 3629.76194(30) cm 01 , respectively, where the uncertainty cited includes an estimate of the uncertainty in the wavenumber calibration. For the 34 SO 2 isotopic species, n 0 (101) was found to be 2475.82917(57) cm 01 . A complete set of rotational and centrifugal distortion constants was obtained for each state. In addition, precise line intensities were determined for each band yielding improved band transition moments. The integrated band intensities at 296 K have been found to be S £ (n 1 / n 3 ) Å 0.539(23) 1 10 018 , S £ (n 1 / n 2 / n 3 0 n 2 ) Å 0.425(18) 1 10 019 , and S £ (2n 1 / n 3 ) Å 0.607(25) 1 10 020 cm 01 / (molecule cm 02 ). The total integrated intensity of the n 1 / n 3 band system was also determined at 0.11 cm 01 resolution from dilute mixtures of SO 2 in N 2 at atmospheric pressure. The value of S £ (n 1 / n 3 ) determined from this technique was 0.537(16) 1 10 018 cm 01 /(molecule cm 02 ), in excellent agreement with the high resolution method. The uncertainties in parentheses are estimated experimental errors.