Tellurium Bromide Iodide

When allyl diphenyl telluronium bromide was treated with iodide in chloroform solution, diphenyl tellurium bromide iodide was isolated on evaporation of the solvent3. Similar reactions with iodine bromide produced only diaryl tellurium dibromides3. 

Intramolecular chalcogen interactions may also stabilize reactive functional groups enabling the isolation of otherwise unstable species or their use as transient intermediates, especially in the case of selenium and tellurium. For example, tellurium(II) compounds of the type ArTeCl are unstable with respect to disproportionation in the absence of such interactions. The diazene derivative 15.23 is stabilized by a Te N interaction. Presumably, intramolecular coordination hinders the disproportionation process. Other derivatives of the type RTeX that are stabilized by a Te N interaction include 8-(dimethylamino)-l-(naphthyl)tellurium bromide, 2-(bromotelluro)-A-(p-tolyl)benzylamine, and 2-[(dimethylammo)methyl]phenyltellunum iodide. Intramolecular donation from a nitrogen donor can also be used to stabilize the Se-I functionality in related compounds." ... 

Tri-p-tolyl tellurium iodide1 melts with decomposition at 232° to 233° C., dissolves readily in methyl alcohol or chloroform, less readily in benzene or ether, and is insoluble in water. Tri-p-tolyl tellurium bromide occurs when the iodide or chloride is boiled with silver bromide. It melts at 265° to 266° C. with decomposition, and dissolves in alcohols or chloroform, but is insoluble in benzene or ether. Tri-p-tolyl tellurium chloride is prepared from the bromide in the usual way. It melts at 260° to 261° C. and gives precipitates with the chlorides of mercury, tin and gold, picric acid and platinic chloride. The hydroxide is a resin, melting at about 110° C., and yielding a pier ate, consisting of long prisms, M.pt. 194° to 195° C.a... 

Tellurium bis[bis(2-hydroxyethyl)dithiocarbamate] and a thirty-fold molar excess of potassium bromide, iodide, or thiocyanate reacted in acetone acidified with acetic acid with replacement of one dithiocarbamate group per two molecules of tellurium dithiocarbamate by halide or thiocyanate. The deep-red crystals are stable as solids but decompose with deposition of tellurium when dissolved in methanol. The single-crystal X-ray structural analysis of the thiocyanato derivative revealed the presence of two chemically different tellurium atoms in the molecule that are in short contact1. 

Aryl tellurium bromides and iodides can be obtained by reaction of diaryl ditellurium compounds with an equimolar amount of bromine or iodine, when the solvent is able to dissolve the starting materials but not the aryl tellurium halide. The precipitation of the aryl tellurium halide prevents it from being converted to aryl tellurium trihalides. The aryl tellurium halides thus far isolated and suitable reaction media for their preparation are listed in Table 3 (p. 240). 

Tabic 3 Aryl Tellurium Bromides and Iodides from Diaryl Ditcllurium Compounds and... 

In contrast to the other aryl tellurium halides, 2-biphenyIyl tellurium bromide and iodide are only slightly associated in solution3. 

The possibility of preparing aryl tellurium halides from equimolar amounts of diaryl ditellurium compounds and aryl tellurium trihalides has hardly been explored. Only phenyl tellurium iodide and 2-biphenylyl tellurium bromide could be obtained by this route. The other aryl tellurium halides (including 3,4-dimethoxyphenyl tellurium chloride) decomposed under the reaction conditions to give diaryl tellurium dihalides and tellurium5. 

Treatment of the 1 1 complexes between phenyl tellurium bromide and ethylenethio- or -selenourea with sodium iodide in warm methanol yielded the corresponding phenyl tellurium iodide complexes5. 

The following compounds were obtained from phenyl tellurium iodide or 4-methoxyphenyl tellurium bromide and organic lithium compounds ... 

Bis[4-methoxyphenyl] tellurium chloride iodide reacted with tetraethylammonium bromide to produce bis[ietraethylammonium] bis[4-methoxyphenyl] dibromodichloro-tellurate(IV). ... 

Because diaryl tellurium diiodides are not hydrolyzed by boiling water, the diaryl tellurium hydroxide iodides were prepared by treating the hydroxide chlorides or bromides with potassium iodide1. 

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°. ... 

Fig. 2. Comparison of the molecular structures of the tellurium(IV) fluoride, chloride, and iodide types in the solid state. The selenium(IV) chlorides and bromides as well as tellurium(IV) bromide and one of the five forms of tellurium(lV) iodide are isostructural to the cubane-like Te4Cli6 molecules (244).

Similarly prepared were solutions of butyl tellurium bromide and vinyl tellurium iodides. ... 

Tris[trimethylsilyl]methyl tellurium iodide reacted with phenylmagnesium bromidebutyl tellurium bromide with vinyl magnesium bromide, vinyl tellurium iodide with butyl and 4-methoxyphenyl magnesium bromide, and 2-propenyl tellurium iodide with 4-methoxyph-enyl magnesium bromide to give the expected unsymmetric dialkyl or alkyl aryl tellurium compounds. 

Phenyl tellurium bromide and 2-(diphenylphosphano)-phenyl lithium reacted in diethyl ether at — 78° to produce 2-(diphenylphosphano)-phenyl phenyl tellurium in 45% yield . Organo tellurium bromides reacted with vinyl magnesium bromides and vinyl tellurium iodides reacted with organo magnesium bromides to give organo vinyl tellurium products in good yields. 

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