First high-resolution analysis of the ν<sub>1</sub>, ν<sub>3</sub> and ν<sub>1</sub> + ν<sub>3</sub> bands of sulphur dioxide <sup>33</sup>S<sup>16</sup>O<sub>2</sub>

2017-01-20T11:34:15Z (GMT) by J.-M. Flaud T.A. Blake W.J. Lafferty
<p></p><p>High-resolution spectra of <sup>33</sup>S<sup>16</sup>O<sub>2</sub> have been recorded for the first time in the 8 and 4 µm spectral regions.</p><p>The ν<sub>1</sub>, ν<sub>3</sub> and ν<sub>1</sub> + ν<sub>3</sub> bands of the <sup>33</sup>S<sup>16</sup>O<sub>2</sub> have been analysed up to very high quantum numbers.</p><p>Accurate ro-vibrational upper states constants have been determined.</p><p></p> <p>High-resolution spectra of <sup>33</sup>S<sup>16</sup>O<sub>2</sub> have been recorded for the first time in the 8 and 4 µm spectral regions.</p> <p>The ν<sub>1</sub>, ν<sub>3</sub> and ν<sub>1</sub> + ν<sub>3</sub> bands of the <sup>33</sup>S<sup>16</sup>O<sub>2</sub> have been analysed up to very high quantum numbers.</p> <p>Accurate ro-vibrational upper states constants have been determined.</p> <p>Fourier transform spectra of sulphur dioxide <sup>33</sup>S<sup>16</sup>O<sub>2</sub> have been recorded in the 8.0 and 4.0 µm spectral regions at a resolution of 0.0015 cm<sup>−1</sup> using a Bruker IFS 125HR spectrometer leading to the observation of the ν<sub>1</sub>, ν<sub>3</sub> and ν<sub>1</sub> + ν<sub>3</sub> vibrational bands of the <sup>33</sup>S<sup>16</sup>O<sub>2</sub> molecule. The corresponding upper state ro-vibrational levels were fit using a Hamiltonian matrix taking into account a Coriolis Δ<i>K<sub>a</sub></i> = 3 resonance between the ro-vibrational levels of the 1<sup>1</sup> and 3<sup>1</sup> vibrational states and a Watson-type Hamiltonian for the ro-vibrational levels of the 1<sup>1</sup> 3<sup>1</sup> vibrational state. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty; i.e. ∼0.20 × 10<sup>−3</sup> cm<sup>−1</sup>. Very accurate rotational and centrifugal distortion constants were derived from the fit together with the following band centres: ν<sub>0</sub> (ν<sub>1</sub>) = 1147.979535(60) cm<sup>−1</sup>, ν<sub>0</sub> (ν<sub>3</sub>) = 1353.335912(60) cm<sup>−1</sup> and ν<sub>0</sub> (ν<sub>1</sub> + ν<sub>3</sub>) = 2487.493732(30) cm<sup>−1</sup>.</p>