Tellurium-nitrogen chlorides

The reaction of Me3SiN=S=NSiMe3 with TeC is a fruitful source of tellurium-nitrogen chlorides that also contain sulfur, as depicted by structures... 

Nitrogen and sodium do not react at any temperature under ordinary circumstances, but are reported to form the nitride or azide under the influence of an electric discharge (14,35). Sodium siHcide, NaSi, has been synthesized from the elements (36,37). When heated together, sodium and phosphoms form sodium phosphide, but in the presence of air with ignition sodium phosphate is formed. Sulfur, selenium, and tellurium form the sulfide, selenide, and teUuride, respectively. In vapor phase, sodium forms haHdes with all halogens (14). At room temperature, chlorine and bromine react rapidly with thin films of sodium (38), whereas fluorine and sodium ignite. Molten sodium ignites in chlorine and bums to sodium chloride (see Sodium COMPOUNDS, SODIUM HALIDES). 

The replacement of rhodium from a wide range of rhodacycles to form condensed furans, thiophenes, selenophenes, tellurophenes and pyrroles has been widely explored and a range of examples is shown in Scheme 97. The rhodacycles are readily generated from the appropriate dialkyne and tris(triphenylphosphine)rhodium chloride. Replacement of the rhodium by sulfur, selenium or tellurium is effected by direct treatment with the element, replacement by oxygen using m-chloroperbenzoic acid and by nitrogen using nitrosobenzene. 

The solution should be free from the following, which either interfere or lead to an unsatisfactory deposit silver, mercury, bismuth, selenium, tellurium, arsenic, antimony, tin, molybdenum, gold and the platinum metals, thiocyanate, chloride, oxidising agents such as oxides of nitrogen, or excessive amounts of iron(III), nitrate or nitric acid. Chloride ion is avoided because Cu( I) is stabilised as a chloro-complex and remains in solution to be re-oxidised at the anode unless hydrazinium chloride is added as depolariser. 

The method (i) can be applied to the synthesis of almost all heavy ketones (Tables 3-5). Silanethiones and a silaneselone stabilized by the coordination of a nitrogen group have been synthesized by the method (ii) (Table 4). The method (iii) is effective to the synthesis of kinetically stabilized tricoordinate heavy ketones, although it cannot be applied to the synthesis of double-bond compounds between heavier group 14 elements and tellurium due to the instability of polytellurides (Table 3). The method (iv) can be used only when the unique dilithiometallanes can be generated (Table 3). The synthesis of heavy ketones by the method (v) demands the isolation of the corresponding heavy acyl chlorides as stable compounds (Table 5). 

Diphenyl telluropyran-4-one (typicalprocedure)7° 120 mL (0.12 mol) of a 1.0 M solution of lithium triethylborohydride in tetrahydrofuran are added to 7.65 g (60 mmol) of powdered tellurium under nitrogen, and the mixture stirred at 20°C for 4 h. A solution of sodium ethoxide (prepared from 5.52 g (0.24 mol) of sodium and 240 mL of absolute alcohol) is added to the dilithium telluride, 13.8 g (60 mmol) of bis(phenylethynyl) ketone are dissolved in a mixture of 150 mL of tetrahydrofuran and 150 mL of 1 M sodium ethoxide in ethanol this solution is poured as quickly as possible into the deep-purple-coloured dilithium telluride soluhon. The flask containing the reaction mixture is immediately placed in a water bath at 50°C and the temperature slowly increased over 30 min until ethanol begins to condense on the side of the flask. The water bath is removed and the mixture is stirred overnight at 20°C. Dichloromethane (400 mL) is then added, the resultant mixture is washed with 800 mL of water, and the organic phase is separated and concentrated to an oil. The oil is dissolved in 600 mL of dichloromethane, and the solution is filtered through a pad of sand. The filtrate is washed with 200 mL of 2% aqueous sodium chloride soluhon, dried with anhydrous sodium sulphate, filtered and evaporated. The brownish solid residue is triturated with 20 mL of butanenitrile and the fine yellow solid is collected by filtration yield 10.9 g (51%) m.p. 126-129°C (from acetonitrile). 

From what has just been said with regard to carbon, it is evident that the atomicity of an element is, apparently at least, not a fixed and invariable quantity thus nitrogen is sometimes equivalent to five atoms of hydrogen, as in ammonic chloride, (i H Cl), sometimes to three atoms, as in ammonia (N" H,), mid sometimes to only one atom, as in nitrous oxide (N,0). But it is found that this variation in atomicity always takes place by the disappearance or development of an even number of bonds thus nitrogen is either a pentad, a triad, or a monad phosphorus and arsenic, either pentads or triads carbon and tin, either tetrads or dyads and sulphur, selenium, and tellurium, either hexads, tetrads, or dyads. 

Tellurium Halides. Tellurium forms the dihalides TeCl and TeBi, but not Tel2. However, it forms tetrahalides with all four halogens. Tellurium decafluoride [53214-07-6] and hexafluoride can also be prepared. No monohalide, Te2X2, is believed to exist. Tellurium does not form well-defined oxyhalides as do sulfur and selenium. The tellurium halides show varying tendencies to form complexes and addition compounds with nitrogen compounds such as ammonia, pyridine, simple and substituted thioureas and anilines, and ethylenediamine, as well as sulfur trioxide and the chlorides of other elements. 

For sulphur nitride, see nitrogen sulphide for selenium, nitride, see nitrogen selenide and for tellurium nitride, see nitrogen telluride. J. von Liebig 26 obtained a brown powder by igniting chromium chloride in ammonia, and he thought the product was elemental chromium. A. Schrotter showed that the product is chromium nitride, Cr2N2 or CrN. 

Phenylazo)phenyl Dialkyldithiocarbamato Tellurium3 A solution of the sodium dialkyldithiocarbamate (1.03 mmol) in 15 ml dry methanol is added under an atmosphere of nitrogen to a stirred solution of 2-(phenylazo)phenyl tellurium chloride (0.35 g, 1.0 mmol) in dichloromethane (25 ml). The mixture is stirred for 20 min at 20°. The solvents are removed on a rotary film evaporator. Dichloromethane is added to the residue. The mixture is vigorously stirred and the solution is filtered to remove the sodium chloride. 

Phenylazo)phenyl tellurium acetate was prepared from the aryl tellurium chloride and sodium acetate. The tellurium atom is in a trigonal bipyramidal environment with the oxygen and one nitrogen atom in the two axial positions1. 

Diisopropyl Ditellurium [Sodium Hydride Method]2 A 500 ml flask fitted with a magentic stirrer and a reflux condenser is purged with nitrogen and charged with 15.0g (0.11 mol) of tellurium and 100 m/ of dimethylformamide (freshly distilled from calcium chloride). 5.64 g of a 50% suspension of sodium hydride (0.11 mol) in mineral oil are added, the mixture is slowly heated over 1 h to 70° with stirring on a water bath, maintained at this temperature for 3 h, and then allowed to cool to 20°. 14.50 g (0.11 mol) of isopropyl bromide are added dropwise over 30 min, the mixture is stirred for 30 min, poured into 200 ml of water, and extracted with three 25 ml portions of chloroform. The combined extracts are washed with three 25 ml portions of distilled water, dried with anhydrous calcium chloride, and the solvent removed under aspirator vacuum. The residue is purified by chromatography on silica gel with hexane as the mobile phase yield 13.5 g (72%) b.p. 92°/2 torr. 

Dibutyl Ditellurium [Rongalite Method]9 Into a 500 ml three-necked flask are placed 9.24 g (0.08 mol) of Rongalite C, 9.0 g (0.23 mol) of sodium hydroxide, and 200 ml of water. The flask is flushed with nitrogen, 15.3 g (0.12 mol) of finely powdered tellurium are added, the stirred mixture is heated under reflux for 5 h under nitrogen, and then 16.4 g (0.12 mol) of butyl bromide are added dropwise. The mixture is then stirred for 30 min, allowed to cool, and extracted with three 100 ml portions of carbon tetrachloride. The combined extracts are dried with calcium chloride, the solvent is removed in vacuum under nitrogen, and the residue is fractionated under vacuum yield 5.1 g (23%) b.p. 112-11571-5 torr. 

Clrioro-4-hydroxyphenyl Tellurium Trichloride3 In a 100 ml flask under an atmosphere of dry nitrogen 5.0 g (18 mmol) of tellurium tetrachloride and 25.0 g (195 mmol) of 2-chlorophenol are heated at 75° until evolution of hydrogen chloride ceases. The precipitated product is filtered, and washed successively with carbon tetrachloride, benzene, and chloroform to remove unreacted starting material. The product is then dissolved in 50 ml of acetone and precipitated by addition of 50 ml of carbon tetrachloride yield 5.3 g (81%) m.p. 166°. 

Dimethylaminophenyl Tellurium Trichloride1 Bis[.V,A-dimcthylanilinium hexachlorotellurate(IV) or the adduct of tellurium tetrachloride with 2 molecules of dimethylaniline is refluxed in excess dry methanol under nitrogen until evolution of hydrogen chloride ceases. The resultant solution is concentrated, the precipitate is filtered, and the solid is extracted with acetone. Benzene is added to the acetone solution, the precipitated crystals are collected, washed thoroughly with chloroform, and dried over anhydrous calcium chloride in a vacuum desiccator yield 80% m.p. 90°. 

Benzeneazophenyl Tellurium Tris[dithiocarbamates]2 To a stirred solution of 1.25 g (3.0 mmol) of 2-benzeneazophenyl tellurium trichloride in 200 ml dichloromethane under an atmosphere of nitrogen is added a solution of 10 mmol the sodium dialkyldithiocarbamate in 100 ml of dry methanol. The mixture is stirred for 0.5 h at 20°. The solvents are removed on a rotary film evaporator. The residue is treated with 200 ml dichloromethane. Insoluble sodium chloride is removed by filtration. Removal of dichloromethane from the filtrate and recrystallization of the residue from methanol produces purple crystals. 

Dibutyl TeUurium (Hydrazine Method)1 To a stirred mixture of 0.40 g (10 mmol) powdered sodium hydroxide, 0.64 g (5.0 mmol) of finely ground tellurium powder, and 10 m/ dimethylformamide are added, dropwise by syringe under an atmosphere of nitrogen at 50- 60° 0.50 ml (7.1 mmol) 80% hydrazine hydrate. The mixture is stirred for 3 h. A solution of 1.4 g (10 mmol) bromobutane in 2 ml dimethylformamide is added and the mixture heated at 60° for 30 min, then cooled to 20°, and extracted with petroleum ether (30 -60°). The organic phase is separated, washed with water, and dried with anhydrous calcium chloride. The mixture is filtered and the solvent evaporated from the filtrate. The residue is purified by preparative TLC (silica gel, Merck 60 GF 254/hexane) yield 57% b.p. 111-114713 torr. 

Z,Z)-Divinyl Tellurium4 To a stirred suspension of 0.383 g (3 mmol) tellurium in 15 ml ethanol kept under nitrogen are added in small portions 0.34 g (9 mmol) of sodium borohydride. The mixture is heated and 0.32 g (8 mmol) sodium hydroxide, 15 m/ water and 5 ml tetrahydrofuran arc added. The mixture is refluxed until all the tellurium has disappeared. When the refluxing mixture has turned yellow (3 to 6 h), it is cooled to 20°, diluted with 50 m/ethyl acetate, and washed with three 30-m/portions of a saturated aqueous solution of ammonium chloride and then with three 30-m/-portions of brine. The organic phase is separated, dried with anhydrous magnesium sulfate, and filtered. The solvent is evaporated from the filtrate on a rotary evaporator at 20 torr. The residue is flash-chromatographcd on silica gel with mixtures of hexane and ethyl acetate. 

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