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 (LiNMR)-Li-7 spectrum at low temperature a 1J(Li,H) coupling is observed. [(Me3Si)2N]2AlH2Li . 2 Et2O 1.