Substituted selenourea-tellurium tetrahalide adducts: Precursors to selenium-tellurium alloys

N,N‐Dimethylselenourea (DMSeU) yields, with TeX4 (X = Cl or Br), a variety of compounds having bonds from selenium to tellurium. Excluding molecules of solvation these compounds display the following stoichiometries: [(DMSeU)4Te]X2, (DMSeU)3(TeX4)2, and (DMSeU)2Te2X6. Tetramethylselenourea (TMSeU) gives, with TeBr4, crystals of (TMSeU)2TeBr4. Both the carbon–selenium and tellurium–halogen bonds undergo hydrolysis under mild conditions to yield precipitates that are alloys of selenium and tellurium. Thus, this group of compounds affords a new approach to the synthesis of selenium–tellurium alloys. Some of the properties of these compounds, as well as the crystal structure of [(DMSeU)4Te]Cl2, are described in this article.