Low Temperature Raman Spectra of Dichlorosulfane (SCl₂), Tetrachlorosulfurane (SCl₄), Dichlorodisulfane (S₂Cl₂) and Dichlorodiselane (Se₂Cl₂)

Abstract

Abstract The Raman spectrum of commercial "sulfur dichloride" shows strong lines due to SCl 2 and S 2 Cl 2 and weak Cl 2 lines at 25 °C, but strong SCl 2 and SCl 4 signals at -100 °C (the latter are superimposed on the S 2 Cl 2 lines). Thus, the intense Raman effect of SCl 4 can be used to detect small amounts of chlorine in SCl 2 . Mixtures of SCl 2 and Cl 2 (1:15) yield the Raman spectrum of SCl 4 at -140 °C, while at 25 °C not trace of this compound can be detected. The spectra of SCl 4 and α-SeCl 4 are quite different, indicating different molecular and/or crystal structures, although ECl 3 + ions (E = S, Se) are present in both cases. While Se 2 Cl 2 dimerizes reversibly below -50 °C, S 2 Cl 2 neither dimerizes nor isomerizes on cooling. The S 2 Cl 2 dimer is characterized by a Raman line at 215 cm -1 the intensity of which was used to calculate an enthalpy of dimerization as of -17 kJ/mol.