On the detection of higher order carbon sulfides (CSx; x = 4-6) in low temperature carbon disulfide ices

Higher-order carbon sulfides - carbon tetrasulfide (CS₄; D_2d), carbon pentasulfide (CS₅; C₂), and carbon hexasulfide (CS₆, C₂) - were detected for the first time via infrared spectroscopy in low temperature carbon disulfide (CS₂) ices upon irradiation with energetic electrons. The identification of these molecules was aided via observed band positions of their C-12 and C-13 isotopologues and the agreement with vibrational modes and isotope shifts predicted from ab initio calculations. Reaction pathways to these species are discussed as well.