Analysis of highly excited ‘hot’ bands in the SO₂ molecule: ν₂ + 3ν₃ − ν₂ and 2ν₁ + ν₂ + ν₃ − ν₂

Abstract

We set up a variational procedure of assignments of transitions and we applied it to the analysis very weak ‘hot’ bands, ν₂ + 3ν₃ − ν₂ and 2ν₁ + ν₂ + ν₃ − ν₂, of the SO₂ molecule. As the first step of the study, the ‘cold’ bands, 3ν₃ and 2ν₁ + ν₃, are re-analysed and transitions belonging to those bands are assigned up to the values of quantum numbers J ^max. = 60, , and J ^max. = 69, for the bands 3ν₃ and 2ν₁ + ν₃, respectively. After ‘cleaning’ the experimental spectrum from transitions belonging to the 3ν₃ and 2ν₁ + ν₃ bands, a variational procedure was used that allowed us to assign 230 and 115 transitions with the values of quantum numbers J ^max. = 35, , and J ^max. = 26, for the bands ν₂ + 3ν₃ − ν₂ and 2ν₁ + ν₂ + ν₃ − ν₂, respectively. The sets of spectroscopic parameters obtained by fitting the assigned experimental transitions reproduce the initial experimental data with an accuracy close to experimental uncertainties.

Keywords:

• sulphur dioxide
• high-resolution spectra
• spectroscopic parameters

Acknowledgements

Authors thank Dr. H.-R. Jauslin for the help in preparing the manuscript for publication. Part of the work benefited from the joint PICS grant of CNRS (France) and RFBR (Russia), 4221N0000211752a from the Russian Science and Innovations Federal Agency under contract No. 02.740.11.0238, and from the grant of the President of Rf, SS-871.2008.2.

Notes

Note

1. The supplementary data can be viewed online.