Lithium Hydrazinidoborane Ammoniate LiN2H3BH3·0.25NH3, a Derivative of Hydrazine Borane

Abstract

Boron- and nitrogen-based materials have shown to be attractive for solid-state chemical hydrogen storage owing to gravimetric hydrogen densities higher than 10 wt% H. Herein, we report a new derivative of hydrazine borane N2H4BH3, namely lithium hydrazinidoborane ammoniate LiN2H3BH3·0.25NH3. It is easily obtained in ambient conditions by ball-milling N2H4BH3 and lithium amide LiNH2 taken in equimolar amounts. Both compounds react without loss of any H atoms. The molecular and crystallographic structures of our new compound have been confirmed by NMR/FTIR spectroscopy and powder X-ray diffraction. The complexation of the entity LiN2H3BH3 by some NH3 has been also established by thermogravimetric and calorimetric analyses. In our conditions, LiN2H3BH3·0.25NH3 has been shown to be able to release H2 at temperatures lower than the parent N2H4BH3 or the counterpart LiN2H3BH3. It also liberates non-negligible amounts of NH3 at temperatures lower than 100 °C. This is actually quite detrimental for chemical H storage, but alternatively LiN2H3BH3·0.25NH3 might be seen as a potential NH3 carrier.

Flexible Borane–Nitrogen Frustrated Lewis Pair Organic Microsphere for Selective Alkyne Hydrogenation

“…At the same time, new peaks formed at 1156 cm –1 for BNP-1 in both cases, which were ascribed to the bending vibration of B–H bond . Together with the perceived weak stretching vibration signal of B–H centered around 2590 cm –1 , a transformation of B–OH­(R) to hydroborane B–H was envisioned.…”

“…At the same time, new peaks formed at 1156 cm −1 for BNP-1 in both cases, which were ascribed to the bending vibration of B−H bond. 53 Together with the perceived weak stretching vibration signal of B−H centered around 2590 cm −1 , 54 a transformation of B−OH(R) to hydroborane B−H was envisioned. This is in line with the previously reported mechanism and can well explain our experimental observation of the inflection point in the reaction evolution chart, during which the truly active B−H species was constantly formed and accumulated (B−H formation stage), thus resulting in a low but increasing substrate conversion rate.…”

Destabilization of Boron-Based Compounds for Hydrogen Storage in the Solid-State: Recent Advances

“…In addition, the heaviest alkali hydrazinidoboranes carry a lower quantity of hydrogen (Figure 19). Some strategies to improve the dehydrogenation performance of alkali hydrazinidoboranes include the use of dopants such as NaH, or obtaining MHB ammoniates [314,315].…”

Sodium borohydride for the near-future energy: a ''rough diamond'' for Turkey

“…We have notably focused on NaBH 4 , 13 that we found to be a potential NH 3 carrier rather than a hydrogen carrier. 175 We use to synthesize all of these compounds, directly or indirectly, from NaBH 4 , and we also used to consider NaBH 4 at first as a precursor of any new targeted boron-based material. In other words, NaBH 4 is a key precursor for synthesizing boron-based materials (Figure 10).…”