MICROWAVE-SPECTRUM FOR BROMO(SULPHIDO)BORON, BRBS

The ratational spectrum of the transient molecule bromo(sulphido)boron, BrB = S, has been observed. The molecule was produced by the high-temperature reaction between gaseous dibromo disulphide, Br2S2, and crystalline boron chips at ca. 1000-degrees-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) angstrom and r(s)(B = S) = 1.608(2) angstrom. Transitions due to vibrationally excited states have also been measured and analysed to yield a range of vibration-rotation parameters.