Six crystalline phases of nonsolvated aluminum hydride were prepared by desolvation of AIH3 etherate in the presence of small amounts of LÍAIH4. The most stable phase, a-AlHj, was prepared both from the solid metastable phases and by crystallizing directly from a refluxing diethyl ether-benzene solution. Both the thermal stability and ease of preparation of aluminum hydride phases are highly dependent upon purity.Aluminum hydride (alane) was first reported as an impure solid* and subsequently as amine2"4 or ether complexes.5 A convenient synthesis of aluminum trihydride diethyletherate was developed by Finholt, Bond, and

Sechs kristalline Phasen von unsolvatisiertem AlH3 werden durch Desolvatisierung von AlH3‐Ätherat in Gegenwart kleiner Mengen LiAlH4 dargestellt.