The submillimeter-wave spectrum and spectroscopic constants of SO 2 in the ground state

The submillimeter-wave spectrum of SO ₂ has been recorded with 0.004 cm ^-1 resolution in the region 8-90 cm ^-1. About 2000 lines were observed, 1500 of which have been assigned to the ground state rotational transitions of ³²SO ₂. Molecular constants up to the 10th order have been derived, combining our data with the available microwave data in the literature. SO ₂ rotational spectrum line positions up to 90 cm ^-1 can be reproduced from these constants, within the experimental accuracy (2 × 10 ^-4 cm ^-1).