Affiliations: Department of Chemistry, University of Oulu, Linnanmaa, FIN-90570 Oulu, Finland
Note: [] Corresponding author.
Abstract: The possibility for the existence of the tellurium-containing chalcogen ring molecules has been explored by use of ab initio molecular orbital techniques. The full geometry optimization has been carried out for all isomers in the series TexS8–x(x=l,2) and TexSeyS8–(x+y) (x=l;y=1,2) at HF/3-21G* level of theory. Each molecule is a crown-shaped eight-membered ring like S8. All calculated bond parameters indicate single bonds and agree with experimental parameters where available. The relative stabilities of the different isomers have been calculated by taking the effects of electron correlation into account involving the second-order Møller-Plessett perturbation theory. The most stable species are TeS7, 1,2,-Te2S6, 1,2-TeSeS6, and 1,2,8-TeSe2S5. The calculations are consistent with the observation that 1,2-Te2S6 and 1,2-TeSeS6, are initially formed when [Ti(MeC5H4)2(Te2)2-Ti(MeC5H4)2] or [Ti(MeC5H4)2(TexE2-x)2Ti(MeC5H4)2] (E=S,Se) are treated with chalcogen chlorides. When (Me3Si)2Te is treated with ClSeS5SeCl, 1,2,8-TeSe2S5 is formed. All these products decompose on standing with the formation of TeS7 and some insoluble material.
Keywords: Tellurium sulfides, tellurium selenium sulfides, ab initio MO calculations, NMR spectroscopy
