Darstellung und Eigenschaften von cyclo-Nonaschwefeloxid (S9O) und von cyclo-Dekaschwefeloxid (S10O) [1] / Preparation and Properties of cyclo-Nonasulfuroxide (S9O) and of cyclo-Decasulfuroxide (S10O) [1]

Abstract

Abstract The homocyclic oxides S9O (m.p. 33 °C, dec.) and S10O (m.p. 51 °C, dec.) have been prepared by oxidation of the corresponding sulfur rings S9 and S10 , respectively, by trifluoroperoxy acetic acid (molar ratio 1:2-3) in a carbon disulfide/methylene chloride mixture. According to infrared and Raman spectra, both compounds contain an exocyclic oxygen atom. S9O and S10O decompose at 25 °C to give SO2 and a polysulfuroxide SnO with >10 but both can be stored at -78 °C without decomposition. The SS bond distances are discussed on the basis of the Raman spectra. In addition, the Raman spectrum of solid S9 has been recorded for the first time. It shows that S9 crystallizes as two allotropes (α-and β-S9) both consisting of cyclic molecules of either C1 or C2 symmetry with bond distances of between 203 and 209 pm.