Isolation of new polynuclear aluminium amides; trinuclear [AlCl(MeNCH2CH2NMe)(2)(Al(NMe2)Cl)(Al(NMe2)(2))] and fluxional adamantane-like [Al4Cl2(NMe2)(6)(NMe)O]

摘要

In attempted transamination reactions involving [Al-2(NMe2)(6)] and the amines, N,N'-dimethylethylenediamine, DMEDA, or diethylenetriamine, DETA, insoluble white powders were formed. Two unexpected compounds, trinuclear [AlCl(MeN-CH2CH2NMe)(2)(Al(NMe2)Cl)(Al(NMe2)(2))] (1) and adamantane-like [Al4Cl2(NMe2)(6)(NMe2)(6)(NMe)O] 2) were isolated in similar reactions where the aluminium amide sample [Al-2(NMe3)(6)] contained some 1% residual chloride. Compound 2 was also identified (by NMR and mass spectroscopy) as the major product from the reaction between Al2Cl6 and LiNMe2 (1:5) in the presence of traces of water. The compounds 1 and 2 have been characterized by X-ray crystallography, mass spectroscopy and NMR. Variable temperature solution phase proton NMR shows that there is inversion at nitrogen in the bridging amides in adamantanoid structure 2. (C) 2000 Elsevier Science S.A. All rights reserved. [References: 18]