Reactions of trimethylamine–iodoborane(1/1) and related complexes in liquid ammonia

The only trimethylamine–halogenoborane(1/1) in the series NMe3·BHyXz(y+z= 3; X = Cl, Br, or I) to react with liquid ammonia is NMe3·BH2I which slowly gives diamminedihydroboron iodide[BH2(NH3)2]I. The reaction rate is greatly increased in the presence of a range of halide salts. On reaction with Na[CN], NMe3·BH2I gives mainly NH3·B(CN)H2 and with Na[NH2] mainly polymeric [BH2(NH2)]n. The complexes NMe3·BBr2H, NMe3·BHI2, and NMe3·BBr3, as well as NMe3·BH2I, react with sodium in liquid ammonia; the products include[BH2(NH2)]n and (for NMe3·BH2I) the borane complex NMe3·BH3.