Sodium telluride

A modification of this method is known When a sodium telluride solution in ethanol at 30°C is treated with l,4-di(trimethylsilyl)buta-l,3-diyne for 3 h, the result is tellurophene in 84% yield (78CB3745). 

Tellur-kohlenstoff, m. carbon telluride. -me-tall, n. metal(lie) telluride. -natrium, n. sodium telluride. -nickel, m. nickel telluride. 

A comprehensive work on the electrodeposition chemistry and characterization of anodically synthesized CdTe thin films has been presented by Ham et al. [98]. In this work, along with the electrolytic anodic synthesis of CdTe by using Cd anodes in alkaline solutions of sodium telluride, an electroless route of anodizing a Cd electrode held at open circuit in the same solution was also introduced. The anodic method was expected to produce CdTe with little contamination from Te on account of the thermodynamic properties of the system the open-circuit potential of Cd anodes in the Te electrolyte lies negative of the Te redox point, so... 

Photovoltaic response parameters for electrodeposited (polycrystalline) CdTe thin film electrodes in sulfide-polysulfide or alkaline sodium telluride PEC have been reported, primarily with no reference to the stability of the cells [100], In view of the instability of CdTe in aqueous solutions, Bhattacharya and Rajeshwar [101] employed two methods for the characterization of their electrodeposited CdTe-based PEC. In the first one, a coating of Pb02 (-100 nm thick) was deposited on the CdTe film surface by electroless deposition, and the coated films... 

Alkali tellurides, among which sodium telluride is the most widely employed, are powerful nucleophilic reagents and therefore react easily with alkylating agents. 

When the alkylating agent is insoluble in liquid ammonia, as in the case of long-chain compounds, an organic solvent is added to the sodium telluride residue after evaporation of the ammonia. Some cyclic and steroidal tellurides have been prepared from sodium telluride in ethanol and the appropriate dihalides. ... 

The use of sodium dithionite (Na2S204) and thiourea dioxide (TUDO HN=C(NH2)S(0)0H) has been introduced later as a reducing agent for the preparation of sodium telluride in an aqueous medium, followed by reaction with n-alkyl halides to give dialkyl teUiirides. - ... 

From sodium telluride and non-activated aryl halides... 

Some concurrent reactions sometimes observed in the above methods (dehydrohalo-genation with the tellurium/Rongalite method and formation of tellurocarbamates RTeC(0)NMe2 with the tellurium/NaH/DMF method) that decrease the yields of the desired tellurides can be avoided by a modified procedure, where sodium telluride is generated by heating elemental tellurium and NaH in NMP. The deep purple solution of the reagent prepared under these conditions can be stored for many days (in contrast to the use... 

From sodium telluride or sodium 0,0-diethyl phosphorotellurolate and arenediazonium fluoroborates... 

Sodium telluride and sodinm 0,0-diethyl phosphorotellurolate, prepared respectively by the Te/NaBH4DMF method and by the reaction of elemental tellurium with NaH and 0,0-diethyl phosphate in ethanol, react with arenediazonium fluoroborates, giving good yields of diaryl tellurides. ... 

This is the most direct route to diorganyl ditellurides and therefore parallels the ronte leading to diorganyl tellnrides, snbstitnting sodium telluride for sodium ditelluride. Sodium ditelluride is prepared employing, with the appropriate ratio of the elements, methods analogous to those described for sodium telluride. 

The low reactivity of aryl halides towards nucleophilic reagents makes their reaction with sodium ditelluride unattractive for the preparation of diaryl ditellurides. Low yields are obtained, like the similar reaction with sodium telluride (see Section 3.1.2.1). 

Sodium telluride, obtained by heating elemental tellurium with sodium hydride in DMF, reacts similarly, leading to symmetrical divinylic tellurides (compare the similar reaction with aryl iodides, see Section 3.1.2.1). 

Under aprotic conditions, aromatic thioketones are reduced by sodium telluride to the corresponding hydrocarbons. ... 

Hydrogen telluride and sodium telluride in a protic solvent easily reduce nitroarenes to anilines. In contrast, sodium telluride in an aprotic solvent exhibits a milder reducing capacity and reduces the nitro compounds only to azo compounds. ... 

Reductive opening of oxiranes with sodium hydrogen telluride and sodium telluride... 

Epoxides bearing a leaving group in a suitable position, such as chloromethyl epoxides, react with sodium telluride (prepared by the Rongalite method), giving allyhc alcohols. ... 

Otherwise, the same products can be obtained by a Knovenagel-type reaction between )3-cyanosulphones and aromatic aldehydes in the presence of sodium telluride (behaving as a base). This result is consistent with the above-formulated desulphonylation of an intermediate a-alkylidene )3-cyanosulphone at the expense of the sodium hydrogen telluride formed during the reaction. 

The title reactions have been performed using sodium telluride in aprotic solvents... 

By treatment with sodium telluride, bromoacetic esters react with aromatic and non-eno-lizable aldehydes in aprotic solvents, giving a, -unsaturated esters. - ... 

The reaction exhibits the following featnres chloroacetates give lower yields than bro-moacetates the E confignration is observed for the formed C=C bond a, -nnsatnrated carbonyl compounds lead only to 1,2-addition prodncts ketones are nnreactive nnder the described conditions a large excess of the bromoacetate and sodium telluride is required to assure high conversions. 

These two classes of compounds can be prepared by treating diphenyl disulphide and aryl sulphonyl chlorides with sodium telluride followed, respectively, by a-halocarbonyl compounds and alkyl halides. 

Common esters such as alkyl and benzyl carboxylates are easily dealkylated by sodium hydrogen telluride, sodium telluride and sodium ditelluride in DMF. In accordance with a typical S 2 displacement at the aUcoxy group carbon, methyl, ethyl and benzyl esters react smoothly. The nucleophilicity of the reagents is enhanced by the polar aprotic solvent, and the reactivity decreases with higher alkoxy chains due to steric hindrance (e.g. 

The haloacetate group, also used as a protecting group for the phenolic function, can be removed by treatment with sodium telluride in DME, giving the parent phenol. ... 

Tellurophene. A mixture of tellurium (4.0 g, 31 mmol), sodium formaldehyde sulphoxylate of 85% (28 g, 200 mmol), sodium hydroxide (17 g, 425 mmol) in 150 mL water is heated at reflux, under N2 atmosphere for 15 min, and then cooled at 20°C. A solution of 1,4-bis(trimethylsilyl)-l,3-butadiene (8.2 g, 42 mmol) in 100 mL of ethanol is slowly added to the stirred sodium telluride solution, the mixture is heated at reflux for 15 min, then stirred at 20°C for 3 h and extracted with ether. The extract is dried (Na2S04), filtered, and 10 mL (200 mmol) of bromine are added dropwise until the bromine colour persists. This solution is concentrated in a water bath under aspiration vacuum to a volume of 50 mL, and the red precipitate of tellurophene dibromide is collected 8.9 g (84%), m.p. 120°C dec. 

Sodium telluride reacts with 1-organo- and l,4-diorgano-l,3-butadyines (prepared in situ by the treatment of the corresponding l,4-dichloro-but-2-yines with NaOH in methanol) to give tellurophenes. ... 

A related compound was prepared by the reaction of 1,2-diiodoacenaphtalene with sodium telluride under aprotic conditions. ... 

Synthesis of compound A.A solution of 1,3-dibromopropane (10.1 g, 0.05 mol) in benzene (100 mL) was added to a solution of sodium telluride (NajTe 17.4 g, 0.1 mol) in ethanol (700 mL). After 3 h sodium borohydride (3.8 g, 0.1 mol) was further added to the mixture to produce sodium propane-1,3-ditellurolate, and then to the mixture was added a solution of the dibromopropane (10.1 g, 0.05 mol) in benzene (100 mL). The whole mixtnre was stirred at room temperature for 2 h. After usual work-up, the crude products were purified by silica gel column chromatography (eluent n-hexane/benzene) to afford compound A, which was further purified by preparative liquid chromatography. 

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