Synthesis and characterisation of bis[(methylthio)carbonyl]polysulphanes

Bis[(methylthio)carbpnyl]polysulphanes with a linear chain of 1-6 sulphurs have been prepared and characterised; in particular X-ray crystallographic analyses proved the structures of the tri- and tetrasulphanes. The tri-to hexa-sulphanes were formed by reactions of O,S-dimethyl dithiocarbonate with the appropriate dichlorosulphane containing two less sulphurs. The disulphane was prepared by chlorination of O-t-butyl S-methyl dithiocarbonate or by controlled desulphurisation of the trisulphane using triphenylphosphine; further desulphurisation provided the monosulphide. (Methylthio)carbonyl-sulphenyl chloride is proposed as an intermediate in the above chlorination; it was synthesised by an indirect route and shown to rearrange to its isomer, (methyldithio)carbonyl chloride.