Infrared and laser Raman spectra of some species of the type Me2YX2 where Y = S, Se, or Te and X is a halogen atom

I.r. and laser Raman spectra of 1 : 1 halogen and interhalogen adducts of dimethyl sulphide, selenide, and telluride, Me2YX2(Y = S, Se, or Te; X = halogen), have been recorded and interpreted in terms of a four-co-ordinate covalent structure of a trigonal bipyramidal type and a charge-transfer formulation of type Me2Y ––– X–X.