Tellurium Monoxide

Tellurium monoxide, TeO. Black solid resulting from thermal decomposition of TeSOj (Te plus SO,). 

Analogous oxides are known containing one atom of sulphur replaced by selenium or tellurium. The tellurium compound, tellurium sulphoxide, STeOa, decomposes with production of tellurium monoxide, TeO, when gradually heated in a vacuum to 225° C.8 Attempts to produce sulphur monoxide similarly from sulphur sesquioxide have not been successful. 

Tellurium Monoxide or Tellurium Suboxide, TeO, is produced when tellurium-sulphur sesquioxide (see p. 389) is heated in a vacuum at 180° to 225° ., the residue being washed with sodium carbonate solution, hot water and finally alcohol 2... 

In dry air tellurium monoxide is a stable, amorphous, grey powder, or a porous solid, to which a graphitic lustre can be imparted by pressure. It is slowly oxidised in moist air and also when heated in dry air, being converted into the dioxide. 

Compared with tellurium and tellurium dioxide, tellurium monoxide is relatively unstable, as can be shown by the ease with which it passes into these two substances, for example when heated strongly in a vacuum or when treated with dilute acids or alkalis ... 

Tellurium and Oxygen Tellurium Monoxide—Tellurium Dioxide and the Tolluritos—Tellurium Trioxide, Telluric Acids and the Tollurates. Tellurium and Sulphur —Tellurium Disulphide, Tellurium Sulplioxide, Tellurium Sulphates, Telluropentathionie Acid. 

Tellurium monoxide, TeO, is obtained by heating TeSOj in a vacuum to 230°, sulfur dioxide being evolved. It is amorphous, brown to black in color, and is easily oxidized. 

Tellurium-oxygen system comprises a wide number of phases. Tellurium monoxide TeO probably exists only in the gas phase. No evidence of its existence in the solid state has been obtained. The He(I) photoelectron spectrum of the molecular beam that has been formed by heating Te02 in vacuo indicates that TeO is the dominant species in the vapor phase.Studies of the absorption and emission spectra of TeO(g) have yielded the bond dissosiation energy of 263.2 kj mol T The Te=0 bond length of 1.828 A.is estimated from the rotational fine structure of the electronic absorption spectrum. 

Diazomethane when heated with copper powder gives nitrogen and an insoluble polymethylene, indicating that one of its reactions is the decomposition into methylene radicals. The methylene radical can also be formed in the gas phase and detected by a mirror experiment.81 The pyrolysis of ketene in the gas phase gives carbon monoxide and methylene radical. The methylene radical both reacts with itself to give ethylene and removes tellurium mirrors, forming tellurform-aldehyde.82 Thus the methylene diradical(P) behaves as expected. 

Tellurium burns in air with a greenish-blue flame. The combustion product is dioxide, Te02, the most stable oxide of the metal. Tellurium also forms other oxides the monoxide, TeO, the trioxide, TeOs, and the pentoxide, Te205. Monoxide has not yet been obtained in solid form. Like sulfur and selenium, tellurium forms oxyacids. Such oxyacids include orthotelluric acid, HeTeOe and tellurous acid, H2Te03, in which the metal is in +6 and +4 valence states respectively. 

Carbonyl Telluride. Litde is known about carbonyl telluride [65312-92-7], COTe. It is formed in poor yield by passing carbon monoxide over tellurium at a high temperature. It is less stable than the selenide. 

Oxidising agents such as nitric acid and potassium permanganate convert the monoxide into the dioxide. Concentrated sulphuric acid has a somewhat similar effect, the red solution primarily produced slowly depositing tellurium sulphate ... 

The monoxide absorbs gaseous hydrogen chloride without any marked change in appearance, but on heating some tellurium dichloride sublimes the direct relationship between these two compounds is thus demonstrated. 

Mass spectral fragmentation of tellurophthalide proceeds through the successive loss of tellurium and carbon monoxide (Scheme 5) (81JHC343), whereas a greater multiplicity of pathways occurs with selenophthalide as indicated in Scheme 6 (72JHC1093). The base peak in the spectra of both selena- and tellura-phthalic anhydride results from loss of COSe(Te), and only very weak ions are observed for the loss of carbon monoxide (78QPP289). 

Ru3(CO)12 reacts with elemental tellurium in n-octane under a CO/H2 pressure of 35 atm to give a mixture of Ru3(CO)9Te2 and Ru3(CO)9H2Te, which may be separated by thin layer chromatography.127 When performed under pure carbon monoxide the yield of the hydrido cluster was... 

Diaryl ditellurium reacted with carbon monoxide at elevated pressures in acetonitrile in the presence of dicobalt octacarbonyl at 125° to give the diaryl tellurium and the Je-aryl tellurolobenzoate12. Formally, these reactions can be considered to be a replacement of one tellurium atom in the diaryl ditellurium by carbon monoxide. Didodecyl ditellurium produced only didodecyl tellurium and no 7e-dodecyl tellurolotridecanoate12. 

Aryl tellurium trichlorides reacted with carbon monoxide (1 atm, 20 atm) at 20° in acetonitrile in the presence of LiCl/PdCl2. palladium(II) acetate, or bis[benzonitrile]... 

Alkyl halides react with sodium benzenetellurolate to yield alkyl phenyl telluriums. These compounds are converted to alkanecarboxylic esters upon treatment with carbon monoxide in methanol in the presence of stoichiometric amounts of triethylamine and palladium(II) chloride2. 

The condensation of aromatic compounds with tellurium tetrachloride produces aryl tellurium trichlorides that can be converted to diaryl ditelluriums, which, in turn, can be reduced to arenetellurols. These tellurols condense with alkyl halides to give aryl alkyl telluriums. When these aryl alkyl telluriums are carbonylated with carbon monoxide in the presence of palladium(II) chloride or acetate, arenecarboxylic acids are formed1-4... 

Acetylenes react with arenetellurolates to form aryl vinyl tellurides. The vinyl groups in vinyl aryl telluriums are converted to vinyl carboxylic acids by carbon monoxide in the presence of stoichiometric amounts of palladium dichloride1 or diacetate2 4. The yield and the product distribution is influenced by the reaction time, the CO pressure, the presence or absence of lithium chloride or triethyl amine, and the concentration of palladium salt. Diphenyl tellurium was converted to benzoic acid1,3. Hexyl phenyl tellurium formed only benzoic acid and no heptanoic acid1. 

These complexes decompose slowly in solution at 20°. When the complex (R = diethylamino) in diethyl ether is treated with carbon monoxide at 100 bar and 60° for 18 hours, tellurium, tungsten hexacarbonyl, and 3-diethylamino-l,l-diphenylpropene (77% yield) were formed3. 

A brief note lacking details claims the preparation of carbon oxide telluride in very low yields by the action of carbon monoxide on tellurium. Carbon oxide telluride is a gas at room temperature1. 

Tellurium formed by irradiation of 235uranium with thermal neutrons may have reacted with carbon monoxide to give carbon oxide telluride2. 

Treatment of diaryl tellurium dichlorides, obtainable from tellurium tetrachloride and aromatic compounds, with carbon monoxide in the presence of palladium(II) chloride/lithium chloride gives arenecarboxylic acids. Biaryls are formed as by-products1,2. Similar products were obtained when the diaryl tellurium dichlorides were reacted with nickel tetracarbonyl3. 

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