Study of methyl chalcogen compounds with ultraviolet photoelectron spectroscopy

Dimethyl sulfide, dimethyl selenide, dimethyl telluride, dimethyl disulfide, dimethyl diselenide and dimethyl trisulfide have been studied by ultraviolet photoelectron spectroscopy. For the first time, the high resolution He(I) spectrum of dimethyl trisulfide is reported. However, the main thrust of this work is to examine trends among related compounds. We report the results of correlations of the first three ionization energies of (CH₃)₂X, X = O, S, Se, and Te and of the correlations of the first five ionization energies of (CH₃)₂X₂, X = O, S, and Se with the ionization energies of oxygen, sulfur, selenium, and tellurium. Where possible, orbital trends of isoelectronic molecules were also examined. Finally, we report the results of correlations of the FWHM of the first three bands of CH₃(S)_nCH₃ with the number of sulfur atoms and investigate convergence of the first two orbital bandwidths to the bandwidths of the two highest occupied bands in μ-sulfur.