Vibronic analysis of the spectrum of Br₂CS

Abstract

[Formula: see text] fluorescence excitation and emission spectra of Br2CS have been recorded. A vibronic analysis shows that the molecule is non-planar in the [Formula: see text] state with an equilibrium out-of-plane angle of 13° and a barrier to inversion of l64 cm−1. Upper state vibrational frequencies of modes 1, 2, 3, 4, and 6 have been obtained. Comparisons with other tetraatomic thiocarbonyls support the assignments. A ground state C—Br dissociation energy of 52.3 kcal mol−1 has been obtained from the onset of diffuseness in the [Formula: see text] spectra. A search for phosphorescence proved unsuccessful.