From Diorgano Ditellurium Compounds and Elemental Halogenes

From Diorgano Ditellurium Compounds and Elemental Halogens 

Fluorination with elemental fluorine diluted 1 20 with nitrogen was used to prepare pentqfluorophenyl tellurium trifluoride from bis[pentafluorophenyl] ditellurium at — 60° with fluorotrichloromethane as the reaction medium. The yield in this reaction was 80%. 4-M ethoxy phenyl tellurium trifluoride was obtained by electrochemical oxidation of the diaryl ditellurium in 0.5 M hydrofluoric acid at platinum electrodes. Bis[pentafluoroethyl] ditellurium and chlorine fluoride (1 6) reacted at — 78° to give pentafluoroethyl tellurium trifluoride, a white solid melting at 95° The same compound was obtained with xenon difluoride as the fluorinating agent and melted at 143° .  

The halogenolysis of dialkyl ditellurium compounds is a convenient method for the preparation of alkyl tellurium trihalides because dialkyl ditellurium compounds are easily accessible through alkylation of disodium ditelluride (p. 258). Diaryl ditellurium compounds generally obtained via reduction of organo tellurium trichlorides (p. 274), serve as starting materials for the syntheses of aryl tellurium tiibromides and triiodides (Vol. IX, p. 1156) that are not obtainable from the hydrocarbons and tellurium tetrabromide or tetraiodide. 

Methyl Tellurium TKchloride All operations are carried out under a nitrogen atmosphere. 5.0 g (17.5 mmol) of dimethyl ditellurium are dissolved in 200 ml of freshly distilled dichloromethane, the reaction flask is cooled, and chlorine is passed rapidly through the solution. When the reaction is complete the red solution abruptly becomes colorless. The mixture is filtered, cooled to — 20°, and the colorless crystals are collected. Concentration and cooling of the filtrate produces an additional crop of crystals yield 6.0 g (63yo) m.p. 137-139° (dec.). 

Sadekov, A.A. Ladatko, V.I. Minkin, Khim. Geterotsikl. Soedin. 1980, 1342 engl. 1016. 

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