On the formation of Al4N12H24 from triethylaluminum and ammonia: A pathway to crystalline AlN with the Wurtzite structure

A mechanism for the formation of the target compound Al4N12H24 from triethylaluminum and ammonia is proposed and studied theoretically at both the PM3 and RHF/6-31G(d,p)//PM3 levels. The highest activation energy during the course of the reactions is about 40 kcal/mol at both levels of theory. Ammonia molecules are shown to play a crucial role in the formation of the target molecule and the reactions are expected to speed up with increased concentration of ammonia, based on the mechanism proposed in this paper. On the other hand, a high concentration of NH3 molecules may increase the concentration of defects and undesired products containing fused rings.