Preparation of spiro-cyclic organic polysulfanes of type C6H10Sn and x-ray structural analysis of C6H10S11, a derivative of cyclo-dodecasulfur

By reaction of (C₅H₅)₂Ti(μ-S₂)₂C₆H₁₀ 3 with S₂Cl₂ 7,8,9,10,11,12-hexathiaspiro-[5.6]dodecane 4 is prepared (yield 51%) and characterized by UV, IR, Raman, mass, and NMR spectra (¹H, ¹³C). The seven-membered CS₆ ring undergoes pseudorotation in solution. With S₇Cl₂ the complex 3 yields 7,8,9,10,11,12,13,14,15,16,17-undecathiaspiro[5.11]heptadecane 5 (yield 23%). The yellow, monoclinic crystals of 5 consist of spirocyclic C₆H₁₀S₁₁ molecules with the C₆ ring in a chair-conformation while the CS₁₁ ring is of the same conformation as cyclododecasulfur S₁₂. UV, IR, Raman, mass and NMR-spectra of 5 are reported. A mixture of dichlorosulfanes S_nCl₂ (n = 1 -8) reacts with 3 to give the homologous series C₆H₁₀S_m which was characterized by reversed-phase HPLC for m = 5 – 14.