Telluronium Chloride

Figure 36 Anion bridging in (a) solid tris(pentafluorophenyl) telluronium chloride and (b) dimesityl(pentafluorophenylseleno) telluronium hexafluoroantimonate...

The reaction of TeCl4 with two or more molar equivalents of 2,2 -dilithiobiphenyl gives dibenzotellurophene and the formulated telluronium chloride as by-product. ... 

Re cry st alii sation of the foregoing green solid from absolute alcohol gives the telluridichloride as primrose-yellow crystals, almost insoluble in benzene, chloroform, carbon tetrachloride or ethyl acetate, slightly soluble in acetone and readily soluble in hot absolute alcohol. Boiling with 95 per cent, alcohol precipitates tellurium dioxide and the tellurium dichloride passes into solution, but on boiling with 90 per cent, alcohol more than 90 per cent, of unchanged dichloride is recovered. When a hot aqueous sodium carbonate solution of the dichloride is acidified with hydrochloric acid the telluronium chloride is precipitated quantitatively. 

Aryl tellurium trihalides accept halide ions from tropylium bromide, ammonium halides, phosphonium halides, arsonium halides, sulfonium chlorides, telluronium chlorides, and diphenyl iodonium chloride to form aryltetrahalotellurates(lV)1-5. 

Refluxing a mixture of tellurium tetrachloride and 1,3-dihydroxybenzene under an atmosphere of nitrogen produced tris[2,-4-dihydroxyphenyl] telluronium chloride (m.p. 129-131°) in 33% yield1. 

The reaction of tellurium tetrachloride (9.3 mmol) with pentafluorophenyl lithium (24 mmol) in diethyl ether/hexane solution gave lris pentafluorophenyl] telluronium chloride (m.p. 188-1900)5. 

Triaryl telluronium compounds can be prepared by the quick addition of a solution of tellurium tetrachloride (1 mol) in diethyl ether to an excess of the Grignard reagents (5 mol) (Vol. IX, p. 1080). Trialkyl telluronium compounds do not seem to be accessible in this manner6. In contract, tellurium tetrachloride and diethyl zinc produced triethyl telluronium chloride (Vol. IX, p. 1080). 

Triphenyl telluronium chloride was obtained from tellurium tetrachloride and the stoichiometrically required amount of triphenyl aluminum8. 

Addition of a concentrated solution of potassium bromide to an aqueous solution of a triaryl or a methyl diaryl telluronium chloride precipitates the telluronium bromides2-5. 

TWs[4-hydroxy-2-methylpheuyl] Telluronium Bromide6 An excess of a solution of potassium bromide in methanol is added to a saturated methanolic solution of the telluronium chloride and mixed thoroughly. Diethyl ether is added to the mixture to complete precipitation of potassium chloride and excess potassium bromide. The mixture is filtered, the filtrate is concentrated under vacuum, and the residue is recrystallized from diethyl ether or acetone yield 90%, m.p. 180 183°. 

When treated with potassium iodide, hot, aqueous solutions of triaryl telluronium chlorides precipitate triaryl telluronium iodides1 (Vol. IX, p. 1080). This halogen exchange reaction was used to isolate triaryl telluronium compounds from the mixtures obtained by reacting tellurium tetrachloride with aryl magnesium bromides (Vol. TX, p. 1080). 

Boiling solutions or suspensions of triorgano telluronium iodides in water or ethanol with an excess of silver chloride produces triorgano telluronium chlorides. Some of the telluronium chlorides were obtained only as oils or tars7. 

Examples of triorgano telluronium chlorides prepared in this manner are ... 

TViphenyl Telluronium Cyanate1 0.15 g (1 mmol) of silver cyanate are dissolved in 850 ml of boiling water, 0.394 g (1 mmol) of triphenyl telluronium chloride dissolved in 50 ml of hot water are added, the mixture is stirred for several minutes, then cooled, and filtered. The filtrate is concentrated to a volume of 5 ml under vacuum, and the concentrate is cooled to 5° and filtered, The filtrate is allowed to stand for 48 h open to the atmosphere, the crystals are collected, crushed, and dried at 24 over phosphorus pentoxide yield 0.34 g (90%) m.p. 152°. Recrystallization from chloroform yields crystals containing 0.5 molecule of solvent. Similarly prepared was diphenyl methyl telluronium thiocyanate (m.p. 1250)2. 

Triphenyl Telluronium Azide1 A solution of 2.6 g (40 mmol) sodium azide in 100 ml of water is shaken with a solution of 2.0 g (5 mmol) of triphenyl telluronium chloride in 200 ml of chloroform. The organic layer is separated, dried with anhydrous magnesium sulfate, filtered, and the filtrate concentrated to a volume of 40 ml. The concentrate is cooled and slowly mixed with cold petroleum ether (b.p. 30-60°), and the precipitate is filtered off yield 1.5 g (80%) m.p. 165° (from toluene). 

Triphenyl telluronium chloride and silver aceto- or benzonitrosolates reacted in liquid ammonia to give triphenyl telluronium nitrosolates11. 

Triphenyl Tellnronium Acetonitrosolate1 3.9 g (10 mmol) of triphenyl telluronium chloride are suspended in 50 ml of liquid ammonia in an apparatus sui table for work with liquid ammonia. To this suspension is added a solution of 1.9 g (10 mmol) of silver acetoni trosolate in 50 ml of liquid ammonia. The mixture is refluxed at the boiling point of liquid ammonia for 1 h, the ammonia is evaporated, and the residue is dried at 20° under high vacuum. 200 ml of methanol are added to the dry residue, the mixture is stirred for 30 min, silver chloride is filtered off, and the bfue filtrate is evaporated to dryness. The residue is recrystallizcd from water and then from liquid ammonia yield 2.9 g (65%) m.p. 139° (dec.). 

Triphenyl Telluronium Tetraphenylborate2 Equimolar amounts of aqueous solutions of triphenyl telluronium chloride and sodium tetraphenylborate arc mixed. The voluminous precipitate is filtered off, washed with water, and recryslallized from dimethylformamide/water m.p. 219". 

Bisftriphenyl Telluronium] Sulfate Pentahydrate7 Aqueous solutions containing stoichiometric amounts of triphenyl telluronium chloride and silver sulfate are mixed. The precipitated silver chloride is removed by filtration. The filtrate is slowly evaporated and the residue is recrystallized from ethanol. 

Bis[diphenyl Methyl Tellnronium] Chromate6 Concentrated solutions of equivalent amounts of diphenyl methyl telluronium chloride and potassium chromate are mixed, the precipitate is collected, and recrystallized from water m.p. 151°. 

Triphenyl Telluromnm / -Diketonates4 A solution of 0.79 g (2.0 mmol) of triphenyl telluronium chloride in the minimal amount of warm water (50-60°) is mixed with 4 mmol of the sodium-/ -dikctonatc dissolved in the minimal volume of water. The precipitate is collected by filtration, washed with three small portions of water, and recrystallized from methanol. 

Triphenyl Telluronium Fluoride1, h 3.3 g (8.6 mmol) of triphenyl telluronium chloride, 1.0 g (4.3 mmol) of silver oxide and distilled water are stirred for 2 h at 20°, the mixture is filtered, and the filtrate is neutralized with hydrofluoric acid. The resultant solution is evaporated under vacuum at 20° and the residue is recrystallized from dry acetone the product melts at 203° with decomposition beginning at 190° m.p. ISO02. 

Triphenyl telluronium chloride and fluoride reacted with xenon difluoride in chloroform at — 10° to form mer-triphenyltrifluoro tellurium3-5. 

Triphenyl tellurium cyanide (triphenyl telluronium cyanide) was prepared by passing an ethanolic solution of triphenyl telluronium chloride through an anion exchange column in the cyanide form1. 

Triphenyl Tellurium Cyanide1 20 g of a Baker CHA-541 resin are treated with aqueous sodium cyanide solution, the column is washed with ethanol/water mixtures with increasing ethanol content, and, finally, the column is covered with 95% ethanol. A solution of 0.1 g (2.5 mmol) of triphenyl telluronium chloride in 60 ml of 95% ethanol is slowly passed through the column. The column is eluted with 200 ml of ethanol, the cluate is evaporated, the oily residue is triturated with ethyl acetate, and the crystals are collected, washed with ethyl acetate, and dried under vacuum yield 0.82 g (85%) m.p. 184° (dec.). 

Tetraphenyl tellurium was similarly obtained in 34% yield from triphenyl telluronium iodide and phenyl lithium1,5. Solutions of tetramethyl tellurium were prepared from trimethyl telluronium iodide and methyl lithium3. The formation of butyl triphenyl tellurium was claimed in a reaction of triphenyl telluronium iodide and butyl lithium4. Equimolar amounts of triphenyl telluronium chloride and 3,3-bis[chloromercuro]-2,4-pentadione in refluxing methanol produced 3-[chloromercuro]-2,4-dioxopent-3-yl triphenyl tellurium6. 

The reaction of tellurium tetrachloride with a least two molar equivalents of 2,2 -dilithiobiphenyl in diethyl ether produced dibenzotellurophene and 2,2 -biphenyldiyl-2-biphenylyl telluronium chloride as by-products1. Dibenzotellurophene was claimed to be formed through reduction of dibenzotellurophene dichloride with dilithiobiphenyl1. 

Tellurium tetrachloride and phenols condense at elevated temperatures to form triaryl telluronium chlorides . The reaction with benzene in refluxing benzene required the presence of aluminum trichloride. ... 

Tris[4-hydroxy-2-metfaylphenyl] Telluronium Chloride A mixture of 4.0 g (37 mmol) of 3-melhylphenol and 5.0 g (18 mmol) of tellurium tetrachloride in carbon tetrachloride is heated under reflux in an inert atmosphere for 30 h, and then allowed to cool. The mixture is filtered, the filter cake is washed thoroughly with carbon tetrachloride and benzene, the solid is extracted with acetone, and the residue is dissolved in methanol. The methanol solution is concentrated, the precipitate is collected, dissolved in methanol, and the product reprecipitated by the addition of acetone yield 2.2 g (25%) m.p. 188-192°. 

IViphenyl Telluronium Chloride A 500 ml, round-bottom flask fitted with a magnetic stirrer and a pressure-equalizing addition funnel is flushed with nitrogen and flame-dried. 300 mloianhydrous toluene and 15.66 g (58 mmol) of tellurium tetrachloride are placed in the flask and a solution of 5.0 g (19.4 mmol) of triphenyl aluminum in 50 ml of anhydrous toluene are placed in the addition funnel. The flask is cooled in ice/water and the triphenyl aluminum solution is added dropwise over 2 h with stirring. The mixture is then rapidly filtered, the yellow solid is washed with 300 ml of anhydrous diethyl ether, the solid is added to 250 ml of water, the slurry is heated until most of the material has dissolved, the hot solution is filtered, and the filtrate is cooled to precipitate the product yield 3.8 g (50%) m.p. 246°. 

---