Theoretical study of the structure and dehydrogenation mechanism of sodium hydrazinidoborane

Alkali-metal hydrazinidoboranes have been recently investigated as a new stable high-capacity material for hydrogen storage, necessitating an exploration of the dehydrogenation mechanism for further developments in this field. Herein, we present a first systematic study of the structure and dehydrogenation mechanism of sodium hydrazinidoborane (NaHB) with three possible pathways considered: pathway A, corresponding to unimolecular dehydrogenation; pathway B, featuring dehydrogenation of the (NaHB)₂ dimer via two different sub-pathways, and pathway C, corresponding to direct dehydrogenation (as compared to B). The calculated rate of the most probable dehydrogenation pathway (B, 3.28min-1) is similar to that obtained experimentally (12.26min-1), supporting the validity of our findings.