Preparation and Dehydrogenation Properties of Lithium Hydrazidobis(borane) (LiNH(BH₃)NH₂BH₃)

LiNH­(BH₃)­NH₂BH₃, the first example of metal-substituted hydrazine bisborane (HBB), is synthesized via the reaction between HBB and n-butyllithium in ether solution. ¹¹B NMR and Fourier transform infrared spectroscopy indicate a new structure, in which one of the N–H bonds is replaced by a N–Li bond. The X-ray diffraction pattern of the product also indicates the formation of a new crystal structure. This compound releases hydrogen at 126 and 170 °C with satisfactory purity and exhibits superior hydrogen storage properties compared with HBB. Differential scanning calorimetry measurement suggests the dehydrogenation reaction of this compound is less exothermic than that of HBB.