Aluminium hydride 

Aluminium hydride can be prepared by below reaction  the solvent can be Et₂O, but the formation of etherate complexes ) Et₂O(_nAlH₃ complicates the synthesis.

Above 423 K, [AlH₃]_n is unstable with respect to decomposition to the elements, and this thermal instability has potential for generating thin films of Al. Aluminium hydride reacts with Lewis bases, e.g. to give Me₃N.AlH₃ in which the Al centre is tetrahedrally coordinated. As is general among the p-block elements, later elements in a group may exhibit higher coordination numbers than earlier congeners, and one example is THF.AlH₃, the solid state structure of which is dimeric, albeit with asymmetrical Al^_H^_Al bridges (Figure 1.1a).

   Despite reports in the 1950s to the contrary, it now seems unlikely that InH₃ and TlH₃ have been prepared. A contributing factor to this is that the In^_H (225 kJ mol^_1) and Tl^_H (180 kJ mol^_1) mean bond enthalpies are significantly less than those of B^_H (373 kJ mol^_1), Al^_H (287 kJ mol^_1) and Ga^_H (260 kJ mol^_1).