PNNL

Abstract

Fourier transform spectra of sulfur dioxide 33S16O2 have been recorded in the 8.0 µm and 4.0 µm 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 33S16O2 molecule. The corresponding upper state ro-vibrational levels were fit using a Hamiltonian matrix taking into account a Coriolis ?Ka =3 resonance between the ro-vibrational levels of the 11 and 31 vibrational states and a Watson-type Hamiltonian for the ro-vibrational levels of the 11 31 vibrational state. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty; i.e., ~0.20 x 10-3 cm-1. Very accurate rotational and centrifugal distortion constants were derived from the fit together with the following band centers: ?0 (?1) = 1147.979535(60) cm-1, ?0 (?3) = 1353.335912(60) cm-1 and ?0 (?1 +?3) = 2487.493732(30) cm-1.