Tellurium bis

Under these conditions, 1,2-dihydroxyethane formed mostly heterocyclic ethylenedioxy tellurium tetrafluoride and only little linear ethylenedioxy bis[tellurium pentafluoride]2. 1,2,3-Trihydroxypropane and an excess of tellurium hexafluoride yielded only one product that contained one heterocyclic tellurium tetrafluoride and one tellurium pentafluoride group2. 

Octafluorocyclopentylenedioxy Bis[tellurium pentafluoride]2 A 30 ml stainless steel cylinder in a dry box... 

When methylene bis[tellurium trichloride] was shaken with an aqueous solution of potassium disulfite at low temperatures, a red-brown crystalline solid was formed that melted over the temperature range 50 to 102°. Elemental analyses suggested that the compound is methylene ditellurium5,s. Mass spectral and NMR data indicate a cyclic structure for the dimeric methylene ditellurium6. 

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 catalyst is allowed to cool under nitrogen, and 400 ml. of bis-(2-methoxyethyl) ether is added from the dropping funnel. The stopper is then temporarily removed to add 20.6 g. (0.05 mole) of bis(4-methoxyphenyl)tellurium dichloride. The mixture is refluxed for 8 hours. Altered while still hot, and the solvent evaporated under reduced pressure (10-20 mm.). The residue was recrystallized from ethanol to afford 8.5-9.8 g. (78-90%) of the product, m.p. 175-176° (Note 9). 

The checkers distilled the anisole from calcium sulfate before use. This reagent functions not only as a reactant, but also as solvent. In some similar preparations the intermediate trichloride is rather insoluble, as in the case of bis(3-methyl-4-methoxyphenyl)tellurium dichloride. The addition of co-solvents such as bis-(2-methoxyethyl) ether is beneficial. ... 

A small amount of tellurium (95 mg.) is formed during the preparation. The amount of tellurium increases slowly as the heating is prolonged. In a separate experiment pure bis(4-methoxyphenyl)-... 

Dimethoxybiphenyl can also be prepared by simply refluxing bis(4-methoxyphenyl)tellurium dichloride with degassed commercial Raney nickel. The yields are, however, lower and less reproducible, and the product may contain some bis(4-methoxyphenyl) telluride. 

Tnfluoromethylation of double bonds or of aromatic nuclei is performed by bis(trifluorotnethyl) tellurium [145] (equation 125)... 

Intramolecular heteroatom coordination may also influence the stabilities or structures of catenated tellurium compounds. For example, a rare example of a tritelluride, bis[2-(2-pyridyl)phenyl]tritelluride, is stabilized by a Te N contact of 2.55 The ditelluride (2-MeOCelFtCOTe) has an unusual planar structure. Although the C=0 Te interaction is longer (3.11 A) than the Me 0 contact (2.76 A), ab initio molecular orbital calculations indicate that the planarity results predominantly from the former intramolecular connection. 

Dibenzo[d,g][l,5]telluroazocines 65 are the only representatives of Te, N-containing eight-membered heterocycles known thus far. Treatment of bis(2-bromomethylphenyl)tellurium dibromide 66 with methylamine followed by reduction of the reaction mixture with sodium sulfide gives, instead of the expected... 

Tellurium, bis(acetophenone)dichloro-photothermography, 6,120 Tellurium, bis(dithiofurancarbamato)-stereochemistry, 1,60 Tellurium, bis(ethyldithiocarbonato)-stereochemistry, 1, 60... 

Tellurium, bis(methyldithiocarbonato)-stereochemistry, 1,60 Tellurium, dichlorodimethyl-lone electron pair, I, 44 Tellurium, pentafluoro-lone electron pair structure, 1,50... 

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