Please check your email for instructions on resetting your password. In addition, the phonon density of states for neat ammonia borane compares well with other spectroscopic results, with the intense peak at 22meV assigned to the librational NH 3 and BH 3 modes, whereas ammonia borane on MCM-41 displays a broad, featureless spectrum indicating a poorly crystalline material. Copyright © 2014 John Wiley & Sons, Ltd. Density. [2][3] The original crystallographic analysis of this compound reversed the assignments of B and N. The updated structure was arrived at with improved data using the technique of neutron diffraction that allowed the hydrogen atoms to be located with greater precision. 3 It has attracted attention as a source of hydrogen fuel, but is otherwise primarily of academic interest. It can be made to release hydrogen on heating, being polymerized first to (NH2BH2)n, then to (NHBH)n,[4] which ultimately decomposes to boron nitride (BN) at temperatures above 1000 °C. Two possible mechanisms of the dehydrogenation of NH3BH3 have been theoretically studied: intramolecular reaction at Ni dicarbene and intermolecular reaction at Ni monocarbene and dicarbene. The Catalytic Dehydrocoupling of Amine–Boranes and Phosphine–Boranes. Mechanism for Forming B,C,N,O Rings from NH 199 Ren'ai Road, Suzhou, 215123 China. Except where otherwise noted, data are given for materials in their,, Creative Commons Attribution-ShareAlike License, This page was last edited on 1 October 2020, at 19:57. Lower densities were measured for polycrystalline pellets (0.73 g cm −3) and were determined from powder XRD (0.74 g cm −3 for the tetragonal phase , , , , and 0.7799 g cm −3 for the orthorhombic one ). Mechanistic insights into tandem amine-borane dehydrogenation and alkene hydrogenation catalyzed by [Pd(NHC)(PCy3)]. The structure of the solid indicates a close association of the NH and the BH centers. Ammonia borane (H3N-BH3, AB) is a lightweight material containing a high density of hydrogen (H2) that can be readily liberated for use in fuel cell–powered applications. and CO Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. DFT studies of dehydrogenation of ammonia–borane catalyzed by [Ir(ItBu′)2]+: A proton transfer mechanism. Ammonia borane is the main product when an adduct of borane is employed in place of diborane:[1]. Synthesis and Application of Organoboron Compounds. Generally adduct are more robust with more basic amines. Investigation of ligand steric effect on the hydrogen gas produced via a nickel-catalyzed dehydrogenation of ammonia-borane utilizing unsymmetrical triazolylidene ligands. InChI=1S/BH3.H3N/h2*1H3 The closest H−H distance is 1.990 Å, which can be compared with the H−H bonding distance of 0.74 Å. Working off-campus? [5] It is more hydrogen-dense than liquid hydrogen and also able to exist at normal temperatures and pressures. First-Principles Study of Intrinsic Defects in Ammonia Borane. Reaction of diborane with ammonia mainly gives the diammoniate salt [H2B(NH3)2]+(BH4)−. Number of times cited according to CrossRef: DFT studies on the Ru-Catalyzed hydrolysis ofAmmonia Borane. The catalytic dehydrogenation mechanism of ammonia borane (NH 3 BH 3, AB) by Ni N‐heterocyclic carbene (NHC) complexes has been investigated by density functional theory. The density of ammonia borane is reported to be 0.78 g cm −3. Dehydrocyclization of diamine borane and amine-borane alcohol catalyzed by 1-lithio-2-alkyl-1,2-dihydropyridine and its Na & K analogues: A DFT analysis of the reaction mechanism. . 3 Ammonia borane (also systematically named amminetrihydridoboron), also called borazane, is the chemical compound with the formula H3NBH3. This interaction is called a dihydrogen bond. for when the gas is used to fuel motor vehicles. [6], Ammonia borane finds some use in organic synthesis as an air-stable derivative of diborane.[7]. Author information: (1)Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland. The B−N distance is 1.58(2) Å. The facile occurrence of the dehydrogenation of AB was demonstrated by the low activation barriers of the rate‐determining step. and you may need to create a new Wiley Online Library account. Use the link below to share a full-text version of this article with your friends and colleagues.