Matrix-Isolation Studies and Ring Conformation of 1,3-Dithietane

Abstract

The infrared and Raman spectra of 1,3-dithietane have been recorded with the sample in the solid state and trapped in an argon matrix at 18K. The number of coincidences between the infrared and Raman spectra of the matrix-isolated sample is consistent with C2v molecular symmetry in which the ring has a puckered conformation. In the solid state a number of bands disappear upon annealing, and the observed mutual exclusion for the annealed solid can be interpreted in terms of D2h, symmetry. Whereas the matrix probably represents the “free” molecule, the planarity of the ring in the annealed solid can be attributed to crystal packing.