Preparation and Dehydrogenation\nProperties of Lithium\nHydrazidobis(borane) (LiNH(BH₃)NH₂BH₃)

Abstract

LiNH­(BH₃)­NH₂BH₃, the first example\nof metal-substituted hydrazine bisborane (HBB), is synthesized via\nthe reaction between HBB and <i>n</i>-butyllithium in ether\nsolution. ¹¹B NMR and Fourier transform infrared spectroscopy\nindicate a new structure, in which one of the N–H bonds is\nreplaced by a N–Li bond. The X-ray diffraction pattern of the\nproduct also indicates the formation of a new crystal structure. This\ncompound releases hydrogen at 126 and 170 °C with satisfactory\npurity and exhibits superior hydrogen storage properties compared\nwith HBB. Differential scanning calorimetry measurement suggests the\ndehydrogenation reaction of this compound is less exothermic than\nthat of HBB.