Accurate spectroscopic characterization of ethyl mercaptan and dimethyl sufide isotopologues : a rute toward their astrophysical detection

Using state-of-the-art computational methodologies, we predict a set of reliable rotational and torsional parameters for ethyl mercaptan and dimethyl sulfide monosubstituted isotopologues. This includes rotational, quartic, and sextic centrifugal-distortion constants, torsional levels, and torsional splittings. The accuracy of the present data was assessed from a comparison to the available experimental data. Generally, our computed parameters should help in the characterization and the identification of these organo-sulfur molecules in laboratory settings and in the interstellar medium.This research was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Community Framework Program under grant No. PIRSES-GA-2012-31754, the COST Action CM1002 CODECS, and the FIS2011-28738-C02-02 project (MINECO, Spain). In Bologna, this work was supported by MIUR (PRIN 2012 funds under the project "STAR: Spectroscopic and computational Techniques for Astrophysical and atmospheric Research") and by the University of Bologna (RFO funds). M.L.S., M.H., and M.A.M. acknowledge the Deanship of Scientific Research at King Saud University for its funding through the Research Group RGP-VPP-333