Rotational spectroscopy of S2O: Vibrational satellites, 33S isotopomers, and the sub-millimeter-wave spectrum

The rotational spectra of disulfur monoxide, S2O, and several of its rare isotopic species have been studied in a supersonic molecular beam by Fourier transform microwave spectroscopy. The strongest lines of S2O were observed by mixing molecular oxygen with sulfur vapor from a heated reservoir at 190 °C, and were so intense that both 33SSO and S33SO were detected in natural abundance, as well as new rotational transitions of 34SSO and S34SO. Vibrationally excited states (v1,v2,v3) up to (0,8,0), combination states (0,v2,1) up to (0,4,1), and the (1,0,0) and (0,0,1) states were also observed in a discharge of SO2 in neon. In addition, the sub-millimeter-wave spectrum of 32S2O has been studied up to 470 GHz in a free space absorption cell through a discharge of sulfur vapor and SO2. An extensive set of molecular parameters for the main isotopic species has been obtained by analyzing all of the presently available rotational and rotation–vibration data.Detection of several new transitions of the SO dimer S2O2 at centimeter wavelengths has yielded an improved set of molecular parameters for its ground vibrational state.