Tellurium tetrachloride

Tellurium tetrachloride, TeC. Colourless solid, m.p. 225 C, b.p. 390, obtained Te plus excess Clj. Hydrolysed by water, forms complexes including [TeClftP ions. 

Caution Because tellurium compounds have toxic effects similar to those of arsenic compounds care should be taken not to bring tellurium tetrachloride and its reaction products into contact with the skin. Avoid breathing fumes and dust of tellurium compounds. In addition, hydrogen chloride is evolved in Step A, and pyrophoric Raney nickel is used in Step B. Therefore all manipulations described in this procedure must be carried out in an efficient fume hood. 

A. Bis i-methoxyphenyl)tellurium Dichloride. In a dry, 500-ml., three-necked, round-bottomed flask equipped with a thermometer and a reflux condenser fitted with a calcium chloride drying tube are placed 27.0 g. (0.1 mole) of tellurium tetrachloride (Note 1) and 64.8 g. (0.6 mole) of dry anisole (Note 2). The mixture is heated to 160 over a period... 

The submitters used tellurium tetrachloride available from E. Merck A G. The checkers purchased the reagent from Research Organic/ Inorganic Chemical Corporation. 

Tellurium tetrachloride reacts as an electrophilic reagent with... 

Tellurium nitride was first obtained by the reaction of TeBt4 with liquid ammonia more than 100 years ago. The empirical formula TeN was assigned to this yellow, highly insoluble and explosive substance. However, subsequent analytical data indicated the composition is Tc3N4 which, in contrast to 5.6a and 5.6b, would involve tetravalent tellurium. This conclusion is supported by the recent preparation and structural determination of Te6N8(TeCl4)4 from tellurium tetrachloride and tris(trimethylsilyl)amine (Eq. 5.5). The TceNs molecule (5.12), which is a dimer of Tc3N4, forms a rhombic dodecahedron in which the... 

This section will focus primarily on a comparison of these ring systems with their heavier chalcogen analogues. The first selenium derivative benzo-l,2,5-selenadiazole was prepared more than 115 years ago by the condensation reaction of selenium dioxide with 1,2-diaminobenzene (Eq. 11.12) and other benzo derivatives may be prepared in a similar manner. The parent 1,2,5-selenadiazole has also been reported. This reagent has been employed to make the tellurium analogue via treatment with ethylmagnesium bromide followed by the addition of tellurium tetrachloride (Eq. 11.13). ... 

The same method was employed for the synthesis of benzo[<2]phenotellurazine 42 and proven to be more efficient. The heterocycle 42 was obtained in 55% yield (89H1007). A possible explanation for the higher yield of 42 is that the transmetallation reaction in this particular case dominates the side formation of nonreactive complex of the amine with tellurium tetrachloride. There is no need for an additional step of the isomerization of the formed aryltellurim trichloride. 

See Tellurium tetrabromide Ammonia Tellurium tetrachloride Ammonia... 

Thioamides have been transformed into the corresponding nitriles. Treatment of primary thioamides by tellurium tetrachloride or selenium tetrachloride in combination with triethylamine affords nitriles.66 Treatment of primary amides and thioamides with l-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) gives nitriles.67 Reactions of thioamides with metal carboxylates in organic solvents enables the selective preparation of nitriles, imides or amides depending on the substitution pattern of the starting material (Scheme 33).68... 

Silicon dibromide sulfide, 0281 Silicon tetralluoride, 4352 Sulfinyl bromide, 0274 Sulfinyl chloride, 4096 Sulfinyl fluoride, 4318 Sulfonyl chloride, 4099 Sulfur dibromide, 0280 Sulfur dichloride, 4113 Sulfur hexafluoride, 4374 Sulfur tetralluoride, 4350 Tellurium tetrachloride, 4175... 

TELLURIUM TETRACHLORIDE 225.5681 -1.3194E+04 -8.0899E+01 4.5316E-02 -1.0441E... 

Tellurium tetrachloride is prepared directly from the respective elements. ... 

Tellurium tetrachloride is a pale yellow crystalline solid, melting point (m.p.) 225°C, highly hygroscopic, soluble in dioxane, acetone, ether, methanol and ethanol but less soluble in benzene and chloroform. 

Tellurium tetrachloride is instantaneously hydrolysed by water, giving tellurium oxochloride, which is soluble in concentrated hydrochloric acid, forming HTeCl and HjTeClg. 

Organyltellurium trichlorides and diorganyltellurium dichlorides are prepared starting from the electrophilic tellurium tetrachloride (or arylteUurium trichlorides) by ... 

In this method, the electrophilic tellurium tetrachloride is employed as starting material to introduce tellurium in organic substrates, in contrast to the preceding methods using nucleophilic tellurium species. 

Tellurium tetrachloride (as well as tellurium tetrabromide and tellurium tetraiodide) reacts with 4 mol equiv of arylmagnesium bromide, giving rise to diaryl teUurides in high yields. ... 

The reduction of organyltellurium trichlorides, which are the primary products of several reactions involving tellurium tetrachloride (see Section 3.5.1), is a useful and general method for the preparation of diorganyl ditellurides. 

Carboxylalkyltellurium trichlorides, obtained by the reaction of tellurium tetrachloride with carboxylic acid anhydrides, are reduced to the corresponding ditellurides with potassium hydrogen sulphite. - ... 

Organyltellurium trichlorides from tellurium tetrachloride and organic substrates... 

From tellurium tetrachloride and ketones and carboxylic anhydrides... 

Reactions involving the attack of a nucleophilic carbon atom activated by an a-carbonyl group at the electrophilic tellurium atom of tellurium tetrachloride belong to the oldest methods of preparative organic tellurium chemistry. 

The addition of tellurium tetrachloride to alkenes produces chloroalkyltellurium trichlorides. Butenes, 1-decene, cycloalkenes, and 3-substituted 1-propenes give mixtures of syn and anti additions. ... 

The alkoxytrihaloteUurination of alkenes or cycloalkenes is afforded by treatment with tellurium dioxide/hydrochloric acid/alcohoF or with tellurium tetrachloride (or tetrabro-mide)/alcohol in carbon tetrachloride. ... 

The condensation of tellurium tetrachloride with aromatic compounds is of general application and has long been used as an efficient route for the preparation of aryltellurium trichlorides. 

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