From Dilithium vic.-Ditellurolates

Dilithium vic-ditellurolates condensed with tetrachloroethene to produce tetratellura-fulvalenes  

Bis dimethylthieno l,4,5,8-tetrateUurafulvalene 3,4-Dibromo-2,5-dimethyl thiophene in tetrahydrofuran is treated at — 78° with 2 equivalents of tert.-butyl lithium. After 2 h one equivalent of tellurium powder is added. The mixture is slowly warmed to 0 and kept at 0 until all the tellurium has dissolved. The mixture is cooled again to — 78°, treated with tert.-butyl lithium and then with tellurium at 0°. The ditellurolate solution is cooled to — 78°, mixed with 0.5 equivalent of tetrachloroethene, stirred for 18 h, and allowed to warm to 20°. The brown solid is isolated by filtration and extracted with carbon disulfide. The extract is evaporated and the residue recrystallized from 1,1,2-trichloroethane to give bronze-colored crystals yield 75% m.p. 295-298°. 

8-Tetratellurafulvalene was prepared in 3 % yield in a multi-step reaction starting with hexamethyldistannane and acetylene . 

Charge-transfer complexes of dicyclopenteno 1,4,5,8-tetratellurafulvalene with a variety of donors such as tetracyanoquinodimethane were prepared. By electrochemical oxidation cation radical salts with chloride, bromide, iodide, hexafluorophosphate, or hexaflu-oroarsenate as anions were obtained . 

The structure of bis[2,5-dimethylthieno] 1,4,5,8-tetratellurafulvalene was determined by single-crystal. X-ray diffraction.  

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