Production and reactions of triplet CS: Matrix infrared and ultraviolet spectra of C2S2

Article abstract of DOI:10.1021/ja00042a024

Matrix infrared and visible-ultravioiet 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/¹²CS₂/¹³CS₂ and Ar/C³²S₂/C³⁴S₂ 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 ^12,13 C and ^32,34S 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∑) from the simple CS₂ discharge requires triplet CS. Evidence was also obtained for other transient cumulene species.