Jepsen, Lars H. Ban, Voraksmy Moller, Kasper T. Lee, Young-Su Cho, Young Whan Besenbacher, Flemming Filinchuk, Yaroslav Skibsted, Jorgen Jensen, Torben R. 2024-01-20T09:33:02Z 2024-01-20T09:33:02Z 2021-09-04 2014-06-12 1932-7447 https://pubs.kist.re.kr/handle/201004/126692 A metal borohydride ammonia borane complex, Mg(BH4)(2)(NH3BH3)(2) was synthesized via a solid-state reaction between Mg(BH4)(2) and NH3BH3. Different mechanochemical reaction mechanisms are observed, since Mg(BH4)(2)(NH3BH3)(2) is obtained from alpha-Mg(BH4)(2), whereas a mixture of Mg(BH4)(2)(NH3BH3)(2), NH3BH3, and amorphous Mg(BH4)(2) is obtained from gamma-Mg(BH4)(2). The crystal structure of Mg(BH4)(2)(NH3BH3)(2) has been determined by powder Xray diffraction and optimized by first-principles calculations. The borohydride groups act as terminal ligands, and molecular complexes are linked via strong dihydrogen bonds (<2.0 angstrom), which may contribute to the high melting point of Mg(BH4)(2)(NH3BH3)(2) found to be similar to 48 degrees C in contrast to those for other molecular metal borohydrides. Precise values for the B-11 quadrupole coupling parameters and isotropic chemical shifts are reported for the two NH3BH3 sites and two BH4- sites in Mg(BH4)(2)(NH3BH3)(2) from B-11 MAS NMR spectra of the central and satellite transitions and MQMAS NMR. The B-11 quadrupole coupling parameters agree excellently with the electric field gradients for the B-11 sites from the DFT calculations and suggest that a more detailed structural model is obtained by DFT optimization, which allows evaluation of the dihydrogen bonding scheme. English American Chemical Society HYDROGEN STORAGE PROPERTIES NUCLEAR-QUADRUPOLE MOMENTS AMMONIA-BORANE MAGNESIUM BOROHYDRIDE LITHIUM AMIDOBORANE MG(BH4)(2) STABILITY CHEMISTRY HYDRIDES Synthesis, Crystal Structure, Thermal Decomposition, and B-11 MAS NMR Characterization of Mg(BH4)(2)(NH3BH3)(2) Article 10.1021/jp502788j 1 The Journal of Physical Chemistry C, v.118, no.23, pp.12141 - 12153 The Journal of Physical Chemistry C 118 23 12141 12153 scie scopus 000337497400008 2-s2.0-84902455662 Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Science & Technology - Other Topics Materials Science Article HYDROGEN STORAGE PROPERTIES NUCLEAR-QUADRUPOLE MOMENTS AMMONIA-BORANE MAGNESIUM BOROHYDRIDE LITHIUM AMIDOBORANE MG(BH4)(2) STABILITY CHEMISTRY HYDRIDES Hydrogen Storage