Synthesis and Structures of some Lithium and Sodium (Aminoalcoholato)hydrido Aluminates

LiAlH4 and NaAlH4 were allowed to react in a 1?:?1, 1?:?2 and 1?:?3 ratio with 2-dimethylaminoethanol, 1-dimethylamino-2-propanol, and ()-N-methylephedrine. Reactions in the 1?:?1 ratio leads to mixtures of M(AlH4n(OR?NMe2)n) in thf solution showing a temperature dependent composition. From the solutions obtained in a 1?:?2 or 1?:?3 ratio the following compounds were isolated as single crystals: (thf)NaAlH2? (OCH2CH2NMe2)2 (2), LiAlH2(OCHMeCH2NMe2)2 (3), LiAlH2(OCHPhCHMeNMe2)2 (4), LiAlH(OCH2CH2NMe2)3 (5), NaAlH(OCH2CH2NMe2)3 (6). All compounds are dimers in the solid state and their Al atoms are pentacoordinated. MHAl bridges were found only in the dihydridoaluminate 2.