Where EP and ER are the energies of the products and the separated reactants, respectively. In figure the atomic structures show that the H2 molecule does not react with AlH3:NMe3 and Al(Me2NEtN t Bu)H2 and we compute very weak interaction energies of -1.41 kJ mol -1 and -3.11 kJ mol -1 respectively. However, H2 reacts favorably with Al(DMP)HCl breaking the Al-C bond to form new C-H and Al-H bonds with a moderate computed interaction energy -36.79 kJ mol -1 . As a consequence, the Al-N dative bond in Al(DMP)HCl is now shorter, changing from 2.11 Å in the precursor to 2.08 Å after interaction with H2. Therefore, with H2 present, complex 2 can decompose through a favorable insertion of H into the original Al-C bond to DMP. In figure NH3 can interact with all three precursors with favorable interaction energies, -36.00 kJ mol -1 for AlH3:NMe3, -76.95 kJ mol -1 for Al(DMP)HCl and -19.51 kJ mol -1 for Al(Me2NEtN t Bu)H2. The Al-N dative bond in AlH3:NMe3 breaks and Al forms a new Al-N bond with NH3 making mono(ammonia)alane. In Al(DMP)HCl, NH3 donates a H to form a C-H bond resulting in the formation of ) after the interaction with NH3. Colour scheme is the same as in figure .