A Barium Complex of the Silanide SiH: Hydride Surrogate and Source of Silicon.

The silanide SiH is an archetypical anion. Its metathesis chemistry is, however, still underdeveloped. We have conveniently prepared the barium silanide complex [(Cbz)BaSiH] with a bulky carbazolide ligand by reaction of the corresponding barium amide with phenyl silane in a good yield. The silanide complex was then used in various metathesis reactions, displaying distinct reactivity toward different substrates. Toward organic substrates such as carbodiimide or benzophenone, the silanide acted as a hydride surrogate, and formamidinate or diphenylmethoxide ligands were formed. Toward the monocoordinated cation [(Cbz)Ge], transfer of SiH was observed, and the decomposition of the silylgermylene [(Cbz)GeSiH] was studied. For the heavier, more easily reducible congeners [(Cbz)Sn] and [(Cbz)Pb] as substrates, [(Cbz)SiH] was obtained under elimination of elemental Sn and Pb, so that formally SiH was transferred to the Cbz ligand.