Extended analysis of the high resolution FTIR spectrum of ³²S¹⁶O₂ in the region of the ν₂ band: Line positions, strengths, and pressure broadening widths

The high resolution infrared spectra of sulfur dioxide (³²S¹⁶O₂) were recorded with a Bruker IFS 125HR Fourier transform infrared spectrometer (Zürich prototype ZP2001) in combination with a Ge:Cu detector and analyzed in the ν₂ fundamental band region (400–650 cm−1, ν₀˜=517.8725691(77) cm−1). More than 4200 transitions were assigned in the experimental spectra to the ν₂ band (the maximum values of the quantum numbers are J^max.=96 and K_a ^max.=25). The subsequent weighted fit of experimentally assigned transitions was made with the Watson Hamiltonian. The 148 highly accurate MW transitions known from the literature have been also taken into account in the fit, resulting in a set of 33 parameters which reproduces the initial 1295 infrared ro–vibrational energy values from more than 4200 experimental line positions with a root mean square deviation drms=1.5×10⁻⁴ cm−1. An analysis of 992 experimental ro–vibrational line intensities of the ν₂ band was made, and a set of four effective dipole moment parameters was obtained which reproduces the initial experimental line intensities with a relative drms=5.7%. The half-widths of 146 ro-vibrational lines (J^max.=53 and K_a ^max.=20) were analyzed from the multi-spectrum fit, and self-pressure broadening coefficients were determined.