Tellurium Dicyanides

Tetraorgano Tellurium, Alkylidene Diorgano Tellurium Compounds, and Hexaorgano Tellurinms 

Cyanide has the possibility of bonding to tellurium via the C atom or the N atom. The v(CN) absorption for nitriles, R-CN, occurs at 2260-2220 cm , and for isonitriles, R-NC, at 2160-2120 cm . However, the single crystal X-ray structural analysis of 4-nitrobenzyl tellurium cyanide showed that the cyanide group is bonded to the tellurium atom via the carbon atom. Thus, di- and triorgano tellurium cyanides are discussed here. 

Diorgano tellurium dicyanides are obtained by treatment of diorgano tellurium dihalides with silver cyanide. Chloroform or acetone served as reaction media. 

4-Dimethylaminophenyl 4-Ethoxyphenyl Tellurium Dicyanide 0.78 g (2 mmol) of 4-dimethylaminophenyl 4-ethoxyphenyl tellurium chloride iodide and 0.6 g (4 mmol) of silver cyanide in 30 ml of chloroform are stirred at 20°. The precipitated silver halides are filtered off and the filtrate is concentrated to give the product yield not given m.p. 192°. 

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Silver cyanide acts on a benzene solution of the tetrabromide, replacing bromine by the cyanogen radical, with simultaneous reduction, the product being a solid tellurium dicyanide ... 

Tellurium Dicyanide, Te(CN)a.—Tellurium tetrabromide and silver cyanide in a suitable organic solvent such as benzene react according to the equation... 

Tellurium dicyanide after a low minutes exposure to air assumes a graphite-like appearance due to the deposition of tellurium. Water and alkalis hydrolyse it with precipitation of tellurium ... 

Tellurium dicyanide was prepared from tellurium tetrabromide and silver cyanide (Vol. IX, p. 932). Tellurium dicyanide, which was found to be quite stable in acetonitrile solution, reacted with excess cyanide ion to form tricyanotellurate(II) as an unstable intermediate3. 

From Dimethyl Tellurium Diiodide and Dimethyl Tellurium Dicyanide... 

Lowry and Gilbert1 claimed that dimethyl tellurium iodide cyanide is formed when dimethyl tellurium diiodide and dimethyl tellurium dicyanide are mixed in ethanol. The compound was not isolated and only a UV-visible absorption spectrum was reported. 

Diaryl tellurium compounds can be obtained in moderate yields from potassium tellurocyanate and arenediazonium tetrafluoroborates in DMSO at room temperature. The potassium tellurocyanate is obtained from tellurium and potassium cyanide in DMSO. Aryl tellurium cyanides are probably formed as intermediates that disproportionate to the diaryl tellurium products and tellurium dicyanide. ... 

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