Tellurium Diperchlorates

Dimethyl tellurium diperchlorate, the only compound of this type that was isolated, was prepared by neutralizing an aqueous solution of the dimethyl tellurium dihydroxide with two equivalents of perchloric acid. Evaporation of the mixture left a syrup that crystallized upon storage in a vacuum desiccator. Dimethyl tellurium diperchlorate melted at 37° 

Solutions of diphenyl tellurium diperchlorate, bis[4-methoxyphenyl] tellurium diperchlo-rate, and telluracyclopentane diperchlorate were prepared by treating the tellurium dichlorides or diiodides in dichloromethane with silver perchlorate. The tellurium diperchlorates were not isolated but reacted with N-,0-, or S -donor molecules to give 1 1 or 1 2 complexes. 

Similar complexes were obtained from bis[4-methoxyphenyl] tellurium diperchlorate including a 1 1 adduct with triphenylphosphane sulfide. Adducts with two moles of ligand per mole of diaryl tellurium diperchlorate could not be obtained even from reaction mixtures containing an excess of the ligand. However, telluracyclopentane diperchlorate formed 1 2 complexes with unidentate ligands and 1 1 complexes with bidentate ligands.  

Diphenyl Tellurium Diperchlorate/Dimethyl Sulfoxide Complex A mixture of 0.70 g (2 mmol) diphenyl tellurium dichloride, 0.83 g (4 mmol) silver perchlorate and 30 ml dichloromethane is stirred at 20° for 1 h. The precipitated silver chloride is removed by filtration. The filtrate is mixed with a solution of 0.15 g (2 mmol) dimethyl sulfoxide in 10 ml dichloromethane. The mixture is refluxed for 5 h. The solvent is distilled from the mixture. The residue is treated with petroleum ether (40-60°). The resulting white solid is recrystallized from petroleum ether (40-60°)/dichloromethane (3 1) and then dried under reduced pressure 95% yield m.p. 140°. 

The same complexes were isolated when a mixture of diaryl tellurium oxide, a shght excess of 70% perchloric acid, and the ligand was refluxed for 10 h . 

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Diphenyl tellurium dichloride and silver perchlorate in dichloromethane were stirred for one hour. The precipitated silver chloride was removed by filtration to give a solution of diphenyl tellurium diperchlorate. This compound was not isolated but treated with O- or N-donors such as pyridine and pyridine N-oxides. The 1 1 adducts were obtained as colorless, crystalline substances in almost quantitative yields. Bis[4-methoxyphenyl] tellurium dichloride and telluracyclopentane 7e-diiodide were similarly converted to the perchlorates2. 

Solutions of diphenyl tellurium diperchlorate in dichloromethane and O-or N-donor molecules, upon refluxing for five hours and concentration of the reaction mixtures, produced 1 1 adducts even in the presence of excess ligands3. 

IR-spectral and conductivity data indicate that in chloroform solution diphenyl tellurium diperchlorate has monodentate, covalently bonded perchlorate groups. The complexes with one monodentatc ligand behave as 1 1 electrolytes1 in acetonitrile and acetone, while, the complexes with two monodentate ligands or one bidentate ligand behave as 1 2 electrolytes2. 

Attempts to isolate diaryl tellurium diperchlorates without ligands either resulted in deposition of tellurium or the isolation of a crystalline compound of unknown structure with strong OH-bands in the IR spectrum1. 

Alkoxyaryl ethoxycarbonylmethyl tellurium compounds reacted with 1,4-bis[dialkylimino]-2,3,5,6-tetrathiacyclohexane diperchlorate in acetonitrile to form as intermediates, 4-alkoxyaryl dialkyldithiocarbamato tellurium compounds that were transformed into 4-alkuxyarylbis[dithiocarbamato] telluronium(II) perchlorates3. 

A mixture of aryl ethoxycarbonylmethyl tellurium and 3,6-bis[dimethylimino]-l,2,4,5-tetrathiane diperchlorate (caution this compound explodes when heated or an impact ) suspended in 40 ml acetonitrile was cautiously heated on a water bath at 60° or kept at 20° overnight. Aryl tellurium bis[dimethyldithiocarbamate] perchlorates were isolated in 70 to 90% yield2. 

Ethoxyphenyl Tellurium Bis[dimethyldithiocarbamate] Perchlorate3 A suspension of 0.70 g (1.6 mmol) of 3,6-bis[dimethyliminio]-l,2,4,5-tetrathiane diperchlorate in acetonitrile is mixed in a beaker with 0.53g (0.36 ml, 1.0 mmol) of 4-ethoxyphenyl ethoxycarbonylmethyl tellurium. The mixture is kept at 20° for 12 h. The precipitate is collected by filtration. Water is added to the filtrate to precipitate additional product. The solids are combined, dissolved in acetonitrile by heating, and reprecipitated by addition of ethanol m.p. 191-193° (dec.). 

Diorgano tellurium oxides react with nitric and perchloric acid producing diorgano tellurium hydroxide perchlorates diperchlorates hydroxide nitrates or dinitrates". ... 

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