Beiträge zur Chemie des Schwefels. 114. Kristall- und Molekülstrukturen vom Hexathiepan (S6CH2), Pentathian (S5CH2) und Dibenzylpentathian (S5C(CH2C6H5)2)

Contributions to the Chemistry of Sulfur. 114. Crystal and Molecular Structures of Hexathiepane (S₆CH₂), Pentathiane (S₅CH₂), and Dibenzylpentathiane (S₅C (CH₂C₆H₅)₂) The crystal and molecular structures of hexathiepane 1 , pentathiane 2 and dibenzylpentathiane 3 were determined by single crystal X-ray structure analyses. 1 : Monoclinic space group P2₁/c; a = 7.694(4), b = 7.668(4), c = 12.367(6) Å, β = 108.9(1)°; Z = 4, d_calc. = 1.986 g/cm₃. The seven-membered heterocycle exists in twist-conformation. 2 : Monoclinic space group C2/c; a = 10.990(5), b = 6.872(4), c = 15.507(6) Å, β = 94.1(1)°; Z = 8, d_calc. = 1.982 g/cm₃. The six-membered heterocycle exists in chair-conformation. 3 : Monoclinic space group P2₁/c; a = 12.907(8), b = 13.611(8), c = 9.408(6) Å, β = 98.9(1)°; Z = 4, d_calc. = 1.442 g/cm₃. 3 is analogous to 2 a six-membered heterocycle with chair-conformation. The benzylic groups are distorted to each other. Bond lengths, bond angles, and dihedral angles of the heterocyclic sulfur rings arc discussed, especially with regard to a comparison with cyclohexasulfur, cycloheptasulfur. and cyclooctasulfur.