A Barium Complex of the Silanide SiH₃^-: Hydride Surrogate and Source of Silicon

The silanide SiH₃^- is an archetypical anion. Its metathesis chemistry is, however, still underdeveloped. We have conveniently prepared the barium silanide complex [(^dtbpCbz)BaSiH₃]₈ 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 [(^dtbpCbz)Ge]⁺, transfer of SiH₃^- was observed, and the decomposition of the silylgermylene [(^dtbpCbz)GeSiH₃] was studied. For the heavier, more easily reducible congeners [(^dtbpCbz)Sn]⁺ and [(^dtbpCbz)Pb]⁺ as substrates, [(^dtbpCbz)SiH₃] was obtained under elimination of elemental Sn and Pb, so that formally SiH₃⁺ was transferred to the ^dtbpCbz^- ligand.