A Synthetic and Theoretical Study of the Aggregation of Amidoaluminium Hydrides: Solid‐State Structure of the Trimethylamine Adduct [(Me3Si)2NA1(Cl)(H) · NMe3]

The amidoaluminium hydride complexes [(Me3Si)2NA1(X)(H) · NMe3], X = H (1), Cl (2), were prepared by the metallation of bis(trimethylsilyl)amine by Al(X)(H)2 · NMe3 (X = H and Cl). The molecular structure of 2 as a monomeric Lewis base adduct with four‐coordinate aluminium centres and terminal amido groups was confirmed by X‐ray crystal structure determination. We also find that bis(trimethylsilyl)amine forms a thermally stable adduct of alane, (Me3Si)2N(H) · AlH3 (3). Ab initio molecular orbital calculations on the possible products arising from these reactions yielding 1 and 2 revealed that the amido‐bridged species, {(μ‐H2N)Al(X)H}2 (X = H and Cl), are favoured over nitrogen donor Lewis base adduct formation, H2NAl(X)(H) · NH3 (X = H and Cl), and then chloro‐bridged, {H2NAl(μ‐X)(H)}2, (X = Cl only), and hydrido‐bridged species, {H2NAl(X)(μ‐H)}2 (X = H and Cl).