Tellurium oxides reactions with

Diorgano tellurium oxides react with an equimolar amount or an excess of a carboxylic acid anhydride to produce diorgano tellurium dicarboxylates in quantitative yields. Chloroform or excess carboxylic acid anhydride served as reaction media. The excess anhydride can be destroyed by boiling in water1. 

Diorgano tellurium oxides react with hydrohalic acids by regenerating the diorgano tellurium dihalides, the common starting materials for the preparation of diorgano tellurium oxides. The reactions with hydrochloric acid, hydrobromic acid , and hydroiodic acid, therefore, are not of synthetic importance. The reaction with hydrofluoric acid , however, is a convenient way of preparing diorgano tellurium difluorides. 

Reactions of the 5 c6>-cubane 3 with chalcogens were also investigated. While mono-chalcogenides are readily produced in the case of sulfur, selenium and tellurium, further reaction with either sulfur or selenium produced only insoluble products. The solid-state structures of the mono-selenide and mono-telluride 65a and 65b (Scheme 2.2.14) revealed that one of the Sn(N Bu)2(NH Bu) sites was oxidized in preference to the unique Sn(N Bu)(NH Bu)2 tin center. Solution-state NMR studies indicated that chalcogen exchange occurs exclusively between the two Sn(N Bu)2(NH Bu) sites. In the case of selenium, in addition to 65a, the selenido-bridged dimer 66 was present in solution as indicated by /sn-Se coupling constants (65a, 3220 Hz 66, 779 Hz). 

Test of Uptake Model Based on a Slow Surface Reaction Combined with Diffusion within the Particle. Since the simple diffusion model is inadequate to describe the uptake behavior of the molybdenum and tellurium oxide vapors by the clay loam particles, a more complex model is required, in which the effects of a slow surface reaction and of diffusion of the condensed vapor into the particle are combined. Consider the condensation of a vapor at the surface of a substrate (of any geometry) and the passage by diffusion of the condensed vapor through a thin surface layer into the body of the substrate. The change in concentration of solute per unit volume in the surface layer caused by vapor condensa-... 

Di-o-tolyl tellurium oxide, (CH3.C6H4)2TeO, occurs when the dibromide is treated with 5 per cent, sodium hydroxide. It separates from toluene as small monoclinic columns, sintering at 199° C. and melting at 205° to 206° C., readily soluble in alcohols, sparingly soluble in benzene or toluene. Its aqueous solution has an alkaline reaction. 

Dimesityl tellurium oxide, [(CH3)3C6H2]2TeO.—The dibromide is quantitatively converted to the oxide by concentrated ammonium hydroxide if sodium hydroxide is used the reaction is very slow. The oxide crystallises as small columns, sintering at 202° C. and melting at 204° to 205° C. It is soluble in the usual solvents, but dissolves only with difficulty in water, giving a neutral solution. 

The tendency of intermediate heterocyclic ditellurides to eliminate one of the tellurium atoms thus contracting the size of the ring is illustrated by the course of the oxidative cyclization of the dilithio dichalcogenides 78 (84JHC413). Whereas in the case of the diselenolate 78 (M = Se) the expected heterocyclic diselenide 79a is formed, albeit in low yield, the analogous reaction with the ditellurolate 78 (M = Te) results in an extrusion of elemental tellurium affording dibenzotellurophene 79b. 

Diorgano tellurium oxides are reduced by hydrazine hydrate to diorgano tellurium compounds. The diorgano tellurium oxides are obtained as the primary products of the reactions of arenetellurinyl acetate or trifluoroacetates with olefins in chloroform, 1,2-dichloroethane, or acetonitrile as reaction media. When the olefin has a hydroxyl group in a f -, y-, or fi-position to the double bond, the addition of the tellurium compound to the double bond is followed by cyclization forming oxacycloalkane derivatives1. 

When the reaction was carried out in chloroform in the presence of ethyl carbamate with boron trifluoride-etherate as catalyst, /J-ethoxycarbonylaminoalkyl phenyl tellurium oxides were formed. These tellurium oxides were not purified but reduced with hydrazine to the corresponding tellurium compounds. ... 

Reactions between benzenetellurinyl trifluoroacetate and cycloalkenes, terminal olefins, or internal olefins in acetonitrile with boron trifluoride-etherate as catalyst produced fi-acetamidoalkyl or -cycloalkyl phenyl tellurium oxides. These oxides were reduced with hydrazine hydrate in ethanol2. 

Alkyl aryl telluriums and diaryl telluriums react with anhydrous (V-chloro-/V-sodioarenesulfonamides in refluxing chloroform in the presence of 18-crown-6 to yield diorgano tellurium arenesulfonimides1. When the reactions are carried out with the hydrated sulfonamides in methanol, diorgano tellurium oxides are formed1. 

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