MgB12H12 is an intermediate in the hydrogen desorption and sorption processes of magnesium borohydride, which is an important candidate material for hydrogen storage. It is thus highly desirable to synthesize anhydrous MgB12H12 in order to study its properties and its role in the hydrogenation and dehydrogenation of magnesium borohydride. Contrary to the literature claim, we find that anhydrous MgB12H12 cannot be obtained from simple thermal decomposition of Mg(H2O)6B12H12·6H2O (1) which has different thermal decomposition behavior from that of most hydrated alkali and alkaline earth salts of dodecahydrododecaborates. Thermal decomposition of 1 involves both dehydration and dehydrogenation processes in three steps, resulting in the formation of complexes Mg(H2O)6B12H12 (2), Mg(H2O)3B12H12 (3), and Mg(μ-OH) x B12H12−x (4) that were characterized by XRD, IR, and 11B NMR. Dehydrogenation was also confirmed by both the generation of hydrogen observed in TPD-MS spectra and the formation of polyhydroxylated complexes.

A simple and efficient way to synthesize unsolvated sodium octahydrotriborate has been developed. This method avoids the use of dangerous starting materials and significantly simplifies the reaction setup, thus enabling convenient large-scale synthesis. The structure of the unsolvated compound has been determined through powder X-ray diffraction.

New convenient procedures for the preparation of ammonia monochloroborane (NH(3)BH(2)Cl) and cyclotriborazane [(BH(2)NH(2))(3)] are described. Crystal structures have been determined by single-crystal X-ray diffraction. Strong H···Cl···H bifurcated hydrogen bonding and weak N-H···H dihydrogen bonding are observed in the crystal structure of ammonia monochloroborane. When heated at 50 °C or under vacuum, ammonia monochloroborane decomposes to (NH(2)BHCl)(x), which was characterized by NMR, elemental analysis, and powder X-ray diffraction. Redetermination of the crystal structure of cyclotriborazane at low temperature by single-crystal X-ray diffraction analysis provides accurate hydrogen positions. Similar to ammonia borane, cyclotriborazane shows extensive dihydrogen bonding of N-H···H and B-H···H bonds with H(δ+)···H(δ-) interactions in the range of 2.00-2.34 Å.

A new ammine complex, Li2B12H12$7NH3, that can reversibly release all the NH3 at below 200oC and reabsorb NH3 at room temperature and 0.5 bar was synthesized and investigated for reversible ammonia storage or indirect hydrogen storage.

DADB synthesis: The diammoniate of diborane (DADB) was synthesized in a new metathesis reaction between the diammoniate of monochloroborane and potassium borohydride in liquid ammonia. (1)H and (11)B NMR spectra of DADB are reported. The stability in THF was examined by variable-temperature (11)B NMR spectroscopy.