Synthesis and Structure of a Novel Cyclic Polysulfide, 2,4,6-Tris[bis(trimethylsilyl)methyl]phenyloctathionane

A novel cyclic polysulfide, octathionane TbtCHS8 (7; Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) was synthesized by thermal reaction of the corresponding diazomethane TbtCHN2 with cyclooctasulfur (S8) in benzene in the dark. Molecular structure of 7 was determined by X-ray crystallographic analysis and the geometry of the CS8 ring was compared with that of theoretically optimized cyclononasulfur (S9). Desulfurization of 7 by triphenylphosphine afforded the corresponding pentathiane TbtCHS5.