Tellurium Cyanide Halides

Diaryl tellurium bromide cyanides and diaryl tellurium iodide cyanides have been prepared. These compounds are colored, crystalline solids with sharp melting points. They are soluble in organic solvents and stable at 20°  

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Cyanogen halides combine with diaryl tellurium in diethyl ether solution to form diaryl tellurium cyanide halides in 80 100% yields1-3. 

Organo tellurium halides treated with potassium or silver cyanide were converted to organyl tellurium cyanides (p. 366). 

Potassium tellurocyanate, prepared from potassium cyanide and tellurium in DMSO, reacts with benzyl halides to produce benzyl tellurium cyanides in good yields. Because of the sensitivity of potassium tellurocyanate to oxygen and of some of the benzyl tellurium cyanides to light, the reactions must be carried out in an inert atmosphere (nitrogen or argon) under red light. 

Tellurocyanate ion reacts with benzyl halides aryl iodides , arenediazonium tetraflu-oroborates, and with azulene" to form aryl tellurium cyanides. 

Pseudohalides of Se in which the role of halogen is played by cyanide, thiocyanate or selenocyanate are known and, in the case of Se are much more stable with respect to disproportionation than are the halides themselves. Examples are Se(CN)2, Se2(CN)2, Se(SeCN)2, Se(SCN)2, Se2(SCN)2. The selenocyanate ion SeCN is ambidentate like the thiocyanate ion, etc., p. 325), being capable of ligating to metal centres via either N or Se, as in the osmium(IV) complexes [OsCl5(NCSe)], [OsCl5(SeCN)], and trans-[OsCU(NCSe)(SeCN)]2-.920) Tellurium and polonium pseudohalogen analogues include Te(CN)2 and Po(CN)4 but have been much... 

From Organo Tellurium Halides and Metal Cyanides... 

Exchange of halide for cyanide in organo tellurium halides occurs easily when the tellurium halide is fused with anhydrous silver cyanide4 or treated with potassium cyanide in methanol5, DMSO6 or ethanol/dimethyl sulfoxide7. 

Diaryl tellurium dichlorides, obtainable from aromatic compounds and tellurium tetrachloride, react with excess bromine or iodine in refluxing DMF or acetonitrile in the presence of a metal fluoride to give aryl halides in low yields. The reactions with chlorinating agents are very sluggish. The reaction of bromine and bis[4-methoxyphenyl] tellurium dichloride formed 2,4-dibromomethoxybenzene in 76% yield. Reactions of these tellurium dichlorides with copper(I) cyanide in DMF produced aryl cyanides in yields of less than 8%3. 

When diaryl tellurium halide cyanides are stirred in chloroform with silver pseudohalides, diaryl tellurium dipseudohalides with the same or different pseudohalides are formed. 

Dimethylaminophenyl 4-Ethoxypheny] Tellurium Dicyanide7 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°. 

The aryl tellurium halides do not have to be isolated but can be generated by reduction of aryl tellurium trihalides and reacted in situ with potassium cyanide s. 

In addition to complex halides and cyanides, the metals form many ammines. Organic compounds of nitrogen, arsenic, sulphur, selenium and tellurium arc other possible ligands. Many complexes with bidentate ligands are known. The various types of isomerism are common thus Pd(NH3)2Cl2 occurs as the pink [Pd (NH3)4] [PdCy and as the yellow cis and trans isomers ... 

Irioxide, platinum, silver, potassium chlorate, potassium ferricyanide, potassium mercuric cyanide, silver chloride, stibine, tellurium halides, tellurium hydropentachloride, tetramethy-lammonium amide, trimethylammonium amide, trioxygen difluoride, vinyl acetate. Violent polymerization with ethylene oxide. Attacks some coatings, plastics, and rubber. Attacks copper, brass, bronze, aluminum, steel, and their alloys. 

Preparation of Sulphides, Selenides, and Tellurides using the Elements Themselves, or Other Inorganic Sulphur, Selenium, and Tellurium Compounds.—Symmetrical sulphides can be obtained in 12—66% yields from an alkyl chloride, sulphur, and NaOH in DMSO. The same system with a bePxZyl cyanide R PhCHCN produces the unsymmetrical sulphides R PhC(CN)SR with an alkyl halide some... 

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