M(Bh3nh2bh2nh2bh3) - The Missing Link In The Mechanism Of The Thermal Decomposition Of Light Alkali Metal Amidoboranes

We report a novel family of hydrogen-rich materials - alkali metal di(amidoborane)borohydrides, M(BH3NH2BH2NH2BH3). The title compounds are related to metal amidoboranes (amidotrihydroborates) but have higher gravimetric H content. Li salt contains 15.1 wt% H and discharges very pure H-2 gas. Differences in thermal stability between amidoboranes and respective oligoamidoboranes explain the release of the ammonia impurity (along with H-2) during the thermal decomposition of light alkali amidoboranes, LiNH2BH3, NaNH2BH3 and NaLi(NH2BH3)(2), and confirm the mechanism of the side decomposition reaction.