Electron-diffraction study of the molecular structure of dimethyldisulphide, (CH3)2S2

Abstract

The molecular structure of (CH₃)₂S₂ has been studied by gas-phase electron diffraction. The results confirm a published microwave study, but are superior in precision. The orientation of the methyl groups was refined and it is established that the C—H bonds are staggered (or nearly so) with respect to the S—S bond. The principal parameters are C—H = 1.090±0.007 Å, S—C = 1.806±0.002 Å, S—S = 2.022±0.003 Å, ∠SSC = 104.1±0.3°; the dihedral angle of the CSSC skeleton is 83.9±0.9°. The S—S length is significantly shorter than found in H₂S₂. The work differs from a standard structure analysis in that two sets of data were used, based on different treatments of the background. Slight differences in some of the less well determined parameters were observed.