A Stable Homoleptic Divinyl Tetrelene Series.

The synthesis of the new bulky vinyllithium reagent (MeIPr=CH)Li, (MeIPr = [(MeCNDipp)2C]; Dipp = 2,6- iPr2C6H3 ) is reported. This vinyllithium precursor was found to act as a general source of the anionic 2σ, 2π-electron donor ligand [MeIPr=CH]- . Furthermore a high-yielding route to the degradation-resistant SiII  precursor MePr•SiBr2 is presented. The efficacy of (MeIPr=CH)Li in synthesis was demonstrated by the generation of a complete inorganic divinyltetrelene series (MeIPrCH) 2 E: (E = Si to Pb). (MeIPrCH)2Si: represents the first two-coordinate acyclic silylene not bound by heteroatom donors, with dual electrophilic and nucleophilic character at the Si II center noted. Cyclic voltammetry shows this electron-rich silylene to be a potent reducing agent, rivalling the reducing power of the 19-electron complex cobaltocene (Cp2Co).