Parent Tellurium Compounds

Another example of the formation of tellurirane using a nonheterocyclic tellurium compound has been shown in the reaction of sodium 0,0-diethyl phosphorotelluroate (45) with a-haloketones (62). As shown in Scheme 11, the starting a-haloketones (62) are converted into the corresponding dehalogenated parent ketones (63) via epitelluride intermediate (64) together with the formation of elemental tellurium. 

Benzo[6]tellurophenes react with halogens (Clz, Br2, I2) and methyl bromide, giving addition products to the tellurium atom, like the parent nonannelated compounds.81,82,M... 

Dialkyl, diaryl, alkyl aryl, and heterocyclic tellurium oxides are known. Most of these compounds are white solids that are soluble in sodium hydroxide. Diorgano tellurium oxides appear to be oxidized by atmospheric oxygen. Their exposure to air should be minimized5. The protonation constant of dimethyl tellurium oxide in water was found to be 6 (pKa)6,7, and of bis[4-methoxyphenyl] tellurium oxide in acetonitrile 14.9s. The barrier to inversion for dihydrogen tellurium oxide (H2Te = 0), the parent compound of diorgano tellurium oxides, was determined as 92.4 kJ/mol (22.0 kcal/mol) by extended Hiickel calculations9. 

The dihalides are susceptible to decomposition by hydrolysis. The dibromides oxidize thiols to disulfides, selenols to diselenides, and diphenyl tellurium to diphenyl tellurium oxide. Hydrazine reduces the dihalides to the parent compounds. ... 

Volatile derivatives of hydrogen cyanide, such as dicyanogen and dicyanides of sulfur, selenium and tellurium, behave in the same way as the parent compound. Such cyanides are formed through p57rolytic transformations. (See the detection of Prussian Blue, page 564.)... 

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