Bronsted and Lewis Base Behavior of Sodium Amidotrihydridoborate (NaNH2BH3)

The reactivity of sodium amidoborane (NaNH2BH3) as a BrOnsted and Lewis base was studied systematically. The [NH2BH3](-) anion can act as a proton acceptor or a hydride donor in different types of reactions. In reactions with very weak BrOnsted acids such as cyclopentadiene, ammonia, and pyrazole, the [NH2BH3](-) anion acts as a proton acceptor through the lone pair on N. The reactions of [NH2BH3](-) with stronger BrOnsted acids are complicated. In the reaction with ammonium chloride or acetic acid, [NH2BH3](-) accepts a proton, reforming NH3BH3. However, in the reaction with HCl or methanol, N-B bond cleavage occurs. [NH2BH3](-) can also donate hydride in some reactions. The possible mechanisms of these reactions are discussed.