First high resolution analysis of the 3ν2 and 3ν2−ν2 bands of 32S16O2

•High resolution analysis of S16O2 FTIR spectra.•Hot transitions.•Determination of spectroscopic parameters.

The second bending overtone band 3ν2 of sulfur dioxide has been studied for the first time with high resolution rotation-vibration spectroscopy. The 1530 transitions involving 728 upper state energy levels with Jmax.= 53 and Kamax.= 15 have been assigned to the 3ν2 band. The 746 transitions belonging to the 3ν2−ν2 “hot” band have been also assigned in the region of 950-1100  cm−1. For the analysis of the assigned transitions, an effective Hamiltonian of an isolated (030) vibrational state (the Watson operator in A-reduction and Ir representation) was used. Set of 9 varied parameters was determined which reproduce the initial experimental data with the drms deviations of 9.0×10−4 cm−1 and 9.8×10−4 cm−1 for the 3ν2 and 3ν2−ν2 bands, which are comparable with the experimental uncertainties.