First high-resolution analysis of the 1, 3 and 1 + 3 bands of sulphur dioxide 33S16O2

HighlightsHigh-resolution spectra of (SO2)-S-33-O-16 have been recorded for the first time in the 8 and 4 mu m spectral regions.The (1), (3) and (1) + (3) bands of the (SO2)-S-33-O-16 have been analysed up to very high quantum numbers.Accurate ro-vibrational upper states constants have been determined. ABSTRACTFourier transform spectra of sulphur dioxide (SO2)-S-33-O-16 have been recorded in the 8.0 and 4.0 mu m spectral regions at a resolution of 0.0015 cm(-1) using a Bruker IFS 125HR spectrometer leading to the observation of the (1), (3) and (1) + (3) vibrational bands of the (SO2)-S-33-O-16 molecule. The corresponding upper state ro-vibrational levels were fit using a Hamiltonian matrix taking into account a Coriolis K-a = 3 resonance between the ro-vibrational levels of the 1(1) and 3(1) vibrational states and a Watson-type Hamiltonian for the ro-vibrational levels of the 1(1) 3(1) vibrational state. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty; i.e. approximate to 0.20 x 10(-3) cm(-1). Very accurate rotational and centrifugal distortion constants were derived from the fit together with the following band centres: (0) ((1)) = 1147.979535(60) cm(-1), (0) ((3)) = 1353.335912(60) cm(-1) and (0) ((1) + (3)) = 2487.493732(30) cm(-1). [GRAPHICS]