Stepwise combination of NH3 with BH4− in metal borohydride ammoniate†
Step-wise combination of NH3 with BH4− was found to proceed in the AlCl3·mNH3–nLiBH4 system. Firstly, only two N–H bonds of the NH3 groups combined with B–H bonds at low temperature. Secondly, the residual N–H bonds could react further with excess B–H bonds at elevated temperature. This process is believed to be a common feature for many metal borohydride ammoniates.