High resolution study of the rotational structure of doubly excited vibrational states of 32S16O18O: The first analysis of the 2ν1, ν1+ν3, and 2ν3 bands

•High resolution analysis of S16O18O FTIR spectra.•Resonance interactions.•Determination of spectroscopic parameters.

The high resolution infrared spectra of the 32S16O18O molecule were recorded with a Bruker IFS 120 HR Fourier transform interferometer for the first time in the region of 1800-2800 cm−1 where the bands 2ν1, ν1+ν3, and 2ν3 are located. About 3970, 2960 and 3450 transitions were assigned in the experimental spectra with the maximum values of quantum numbers Jmax./Kamax. equal to 59/20, 68/25, and 43/18 to the bands 2ν1, ν1+ν3, and 2ν3, respectively. The subsequent weighted fit of experimentally assigned transitions was made with the Hamiltonian model which takes into account the resonance interactions between the studied vibrational states. As the result, a set of 39 fitted parameters was obtained which reproduces the initial 3213 ro-vibrational energy values obtained from the assigned transitions with the drms=2.4×10−4cm−1.