Disodium tetraphenylethylene

The first experimental hint for a finite lifetime of an alkyl halide anion radical in homogeneous etheral solution was provided by Garst and coworkers in 1977. From the reduction of 5-hexenyl chloride, bromide and iodide with disodium tetraphenylethylene in 2-methyltetrahydrofuran (MTHF) at 20°C they concluded that radical anions R-X Na were involved and that the order of their stability was R-I Na" >R-Br Na > R-CrNa. ... 

The resulting R- can suffer one of two fates, coupling with a polyacetylene radical or subsequent reduction to a carbanion, the latter affording reduction products. The mechanism is identical to that proposed for the reaction of disodium tetraphenylethylene with alkyl halides. - S... 

Two complexes containing a dilithiated stilbene fragment have been prepared and isolated from the reactions of 1,2-diphenylethane with N-chelated butyl-lithium reagents. " The molecular and crystal structures of these compounds, stilbene bis(lithium tetramethylethylenediamine) (Figure 4a) and stilbene bis(lithium pentamethyldiethylenetriamine) (Figure 4b), have been determined by X-ray diffraction techniques. Each structure contains two amine-solvated Li atoms located above and below the olefinic bond of a stilbene molecule. The stilbene molecule is planar in both structures, and is in a trans configuration about the C(7)—C(7 ) bond, which is ca. 0.01 nm longer than that in trans-stilbene. " The optical and "C n.m.r. spectra of THF solutions of the related dilithium and disodium salts of tetraphenylethylene dianion, as well as the spectra of their mixtures, have been examined. " The data can be rationalized in terms of the... 

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