Structures of Two Highly Reactive Intermediates upon LiAlH₄ Reduction in the Solid State and in Solution: [(Me₃Si)₂NAlH₃Li · 2Et₂O]₂ and [(Me₃Si)₂N]₂AlH₂Li · 2Et₂O

A central kite-shaped AlH2Li ring in which the Li atom bridges the two hydride ligands bound to the Al atom is found in an intermediate of the reaction of HN(SiMe3)2 with LiAlH4. The bond angles show that compound 1 is relatively strained. Nevertheless, 1 does not dissociate in solution; in the 7Li NMR spectrum at low temperature a 1JLi, H coupling is observed.