Reactions of Hydrazines with AlH3·NMe2Et – Formation of Aluminum‐Nitrogen Heterocycles

Treatment of the alane–amine adduct AlH3·NMe2Et with 1,2-diphenylhydrazine, H5C6–N(H)–N(H)–C6H5, afforded a five-membered Al2N3 heterocycle (1) by the elimination of hydrogen and partial cleavage of N–N bonds. The structure of 1 comprises two aluminum atoms bridged by a dianionic diphenylhydrazinediido (–H5C6–N–N–C6H5–) and an imido ligand (H5C6–N2–). Each aluminum atom is further attached to a terminal hydrogen atom and a (ethyl)dimethylamino group. 1-Aminopyrrole, H2N–NC4H4 gave a singular tricyclic cage compound (2) under similar conditions. The amino groups were completely deprotonated. N–N bond cleavage was not observed. Compound 2 possesses a central Al2N2 ring. Its nitrogen atoms are bridged by an Al2N group, whereas an N2Al group bridges both aluminum atoms. All nitrogen atoms are part of N–N bonds, and all metal atoms are further bonded to terminal hydrogen atoms. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)