PRODUCTION AND REACTIONS OF TRIPLET CS - MATRIX INFRARED AND ULTRAVIOLET-SPECTRA OF C2S2

Matrix infrared and visible-ultraviolet absorption spectroscopy and ab initio electronic structure calculations have been used to characterize the reaction products from a Tesla coil Ar/CS2 discharge. The discharge is an excellent source of CS, which reacts with other molecules to form the major C3S2 product and the transient C2S2 species. The spectra of discharged mixed isotopic samples (Ar/CS2/CS2)-C-12-C-13 and (Ar/CS2/CS2)-S-32-S-34 exhibit triplet patterns in the CS antisymmetric stretching region, which unambiguously identifies the new C2S2 molecule with two equivalent CS subgroups. The magnitudes of the C-12, C-13 and S-32, S-34 isotopic shifts further characterize the diatomic CS subgroup nature of C2S2. Another product contains two equivalent CS subgroups interacting with inequivalent S atom(s). The formation of C2S2 (3-SIGMA) from the simple CS2 discharge requires triplet CS. Evidence was also obtained for other transient cumulene species.