From Diaryl Tellurium Dihalides

When refluxed in acetonitrile or 1,4-dioxane, diphenyl tellurium dichloride and silver salts of dicarboxylic acids produced polymeric diphenyl tellurium carboxylates .  

Polymeric Diphenyl Tellurium Sebacate An equimolar mixture of diphenyl tellurium dichloride and disilver 1,10-decanedioate in acetonitrile is heated under reflux for 4.5 h. The mixture is then filtered, the solids are extracted with hot benzene, the extracts are evaporated, the residual oil is dissolved in hot acetone, and the acetone is allowed to cool whereupon the product crystallizes yield 35%, m.p. 164-166°. 

---

The possibility of preparing aryl tellurium halides from equimolar amounts of diaryl ditellurium compounds and aryl tellurium trihalides has hardly been explored. Only phenyl tellurium iodide and 2-biphenylyl tellurium bromide could be obtained by this route. The other aryl tellurium halides (including 3,4-dimethoxyphenyl tellurium chloride) decomposed under the reaction conditions to give diaryl tellurium dihalides and tellurium5. 

Examples of diaryl tellurium dihalides similarly prepared1 from diphenyl ditellurium are ... 

Higher-valent metal halides oxidize diaryl tellurium compounds to diaryl tellurium dihalides. Copper(II) halides can be generated in the reaction mixture from easily accessible copper(II) acetate and hydrohalic acids4. These halogenation reactions are convenient alternatives to the methods using corrosive elemental halogens or sulfuryl halides. 

Diaryl tellurium dihalides in toluene solutions reacted with aryl magnesium bromides in diethyl ether to yield triaryl telluronium salts in yields ranging from 6 to 78% (Vol. IX, p. 1082/3)3-5. Aqueous solutions of the products were generally treated with potassium iodide to convert the telluronium halides to telluronium iodides3,4. 

Diaryl ditellurium compounds were similarly obtained from the following aryl alkyl tellurium dihalides ... 

Diorgano tellurium dihalides were prepared in this manner from dialkyl, alkyl aryl, and diaryl tellurium compounds, and from tellurium heterocycles. However, 1-oxo-1,3-dihydro-2-benzotellurophene experienced ring cleavage when reacted with sulfuryl chloride7. 

---