Millimeter- and submillimeter-wave spectroscopy of HBS and DBS in vibrationally excited states

Normal and deuterated isotopic variants of thioborine have been produced in the gas phase by a high temperature reaction between crystalline boron and hydrogen sulfide. Millimeter- and submillimeter-wave rotational spectra have been recorded in the frequency range from 75 to 730 GHz for vibrational ground and excited states of the H10/11B32S and D10/11B32S isotopic species. The spectra of all the excited states which lie below 1500 cm−1, that are 0110, 0001, 0200, and 0220, have been observed and analyzed for each of the four isotopologues investigated. High-order Fermi resonance parameters were found important to analyze properly the spectra of the 0001 and 0200 interacting states. The improved rotational data in conjunction with earlier infrared spectroscopy results have been employed to calculate more precise anharmonic force constants and equilibrium bond lengths.