Microwave spectrum for bromo(sulphido)boron, BrBS

Abstract

The rotational spectrum of the transient molecule bromo(sulphido)boron, BrBS, has been observed. The molecule was produced by the high-temperature reaction between gaseous dibromo disulphide, Br₂S₂, and crystalline boron chips at ca. 1000 °C, and was studied by microwave spectroscopy between 26.5 and 40 GHz. The spectrum is that of a linear molecule. Ground-state rotation, distortion and quadrupole coupling constants have been obtained for 10 of the 12 isotopic variants in natural abundance. A wealth of spectroscopic data has been obtained which has allowed an extremely detailed structure analysis to be performed. The resulting bond lengths are r_s(BrB)= 1.831(2)Å and r_s(BS)= 1.608(2)Å. Transitions due to vibrationally excited states have also been measured and analysed to yield a range of vibration–rotation parameters.