Rotational spectra of S- and S-containing isotopologues of laser ablation generated tin monosulfide

Using a newly constructed source, tin monosulfide is produced by the reaction between carbonyl sulfide and the products resulting from the ablation of tin metal by the pulsed output of a frequency-doubled Nd:YAG laser (λ = 532 nm). Entrained in argon carrier gas, SnS is introduced into the cavity of a Balle-Flygare Fourier transform microwave spectrometer that has a frequency range encompassing the two lowest rotational transitions (J = 1 − 0 and 2 − 1) for this molecule. Except for ¹¹⁵Sn³⁴S, spectra are obtained in natural abundance for all ³⁴S-containing isotopologues with naturally occurring tin isotopes. Additionally, spectra were obtained for the rare isotopologues, ¹¹⁵Sn³²S and ¹²⁰Sn³³S. Resolution of the hyperfine structure in the latter species allows a more precise determination of its ³³S nuclear quadrupole coupling constant. Spectra for all species containing ³⁴S are analyzed in terms of mass-independent Dunham parameters and are combined with all available isotopologues to determine Born-Oppenheimer breakdown terms for both tin and sulfur.