Polyatomic Cations of Sulfur, Selenium, and Tellurium

The preparation and properties of homopolyatomic cations of the Group VI elements have been reviewed recently.1 The general method described below, involving the oxidation of elemental sulfur, selenium, and tellurium with either antimony pentafluoride or arsenic pentafluoride in liquid sulfur dioxide, is convenient for the preparation of compounds containing these polyatomic cations. The procedure is basically that briefly described previously2 for the preparation of Se8(Sb2F j i )2. 

Selenium and tellurium and their compounds produce very unpleasant and dangerous physiological reactions. They are hazardous both through inhalation as dusts and through skin absorption from solution. Because of these properties and because of the toxicity of the sulfur dioxide used as a solvent, the reactions should be conducted in an efficient fume hood. Rubber gloves and apron are recommended to prevent contact with solutions containing selenium and tellurium compounds as well as the dangerous pentafluorides of antimony and arsenic. 

Liquid sulfur dioxide solutions can generate up to 5 atmospheres pressure at room temperature. Therefore, the handling of such solutions in sealed glass equipment requires careful shielding including the use of face shields. 

Oxidation Reactions with Antimony Pentafluoride. An appropriate amount of the finely powdered element is introduced into A (Fig. 

Oxidation Reactions with Arsenic Pentafluoride. Arsenic penta-fluoride (Ozark Mahoning Company) is handled on a calibrated Pyrex vacuum line equipped with a mercury manometer. The vacuum line is thoroughly flamed out under vacuum before use. The joints on 

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Table 12-3 Polyatomic Cations of Sulfur, Selenium, and Tellurium...

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