DiTelluride, sodium

Three main routes have been well established for the preparation of diorganyl ditellurides (1) The reaction of sodium ditelluride with alkylating or arylating agents. 

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). 

This method was later revised replacing sodium ditelluride by potassium ditelluride. ... 

Dialkyl and diaryl ditellurides are easily converted into the corresponding tellurium trichlorides by means of the fission of the Te-Te bond by a chlorinating reagent. This route is very suitable for the preparation of the alkyl derivatives in view of the easy accessibility of dialkyl ditellurides via the alkylation of sodium ditelluride (see Section 3.2.1). 

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. 

Interestingly, when 2,3 6,7-bis(trimethylene)naphthalene is treated with sodium ditelluride in HMPTA or 1,3-dimethyl-2-imidazolidinone solution,... 

Telluranthrene was obtained in trace amounts (3%) by the reaction of o-dichlorobenzene with sodium telluride (88M13) and in somewhat higher yield (12%) by the reaction of o-diiodobenzene with sodium ditelluride (91 KGS 1203). It is worth nothing that the analogous reaction of o-dibromobenzene with sodium diselenide leads not to selenanthrene but to poly(o-phenylene)diselenide in 26% yield (87IC1664). 

When heated in dimethylformamidc at 140-150° sodium ditelluride and 1,4-diiodobenzene produced a black, amorphous polymer that decomposed at 230-25005. 

Sodium ditelluride, prepared from the elements in dimethylformamide, reacted with 5,6,11,12-tetrachloronaphthacene2 and with 7,8-dichloro-l,2-diselenanaphthacene3 to produce the compounds I and II. Crystal and molecular structures for these compounds were determined2,4. 

Based on this unfortunate result, 119 was envisioned a synthesis of the elusive 1,6-epitelluro 119. Thus, the above sequence was repeated but with sodium ditelluride as the reagent the only product formed was that from a simple base-induced elimination, the alkene 118 <2005AJC188>. A very similar study has been published by an Indian... 

Dihydroacenaphtho[5,6-cfi(]-l,2-diselenole (65) was prepared from 5,6-dibromoacenaphthene via the dilithio derivative <80TL4565,88BCJ2013). The ditelluro compound (3), however, could not be prepared by this method but was synthesized by reaction of sodium ditelluride with 5,6-dichloro-acenaphthene in HMPA <88BCJ2013>. 

From fluorest nce X-ray measurements, the percentage of bromine present in the polymers was found to be less than 1% of that of tellurium, suggesting that the end groups are bromides [209]. Like any other polycondensation reactions, formation of cyclics also occurs along with that of the primer. For example, the reaction of n-butyldiiodide with sodium ditelluride results in the formation of the polymer along with the six-membered cydic ditelluride [234] ... 

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