Chemical Evidence for the Structure of the “Diammoniate of Diborane.” V. A Tracer Study of the Reaction between Sodium and the “Diammoniate of Diborane”

Cyclic Hydroborate Complexes of Metallocenes. 1. Organodiborate Ring Transformations Promoted by Zirconocene and Hafnocene Dichlorides. Syntheses and Structures of Zirconocene and Hafnocene Boracyclopentane Derivatives

“…In ammonia, the bridge system undergoes heterolytic cleavage at −40 °C to yield [H 2 BC 4 H 8 ] - and the solvent-separated cation [(η 5 -C 5 H 5 ) 2 ZrCl(NH 3 ) x ] + (reaction 3a). Evidence for the ionic product is given by a clean 11 B NMR spectrum which is a sharp triplet at −20.8 ppm ( J ( 11 B, 1 H) = 76 Hz) at −40 °C that is assigned to [H 2 BC 4 H 8 ] - . This reaction parallels the unsymmetrical cleavage of B 2 H 6 by NH 3 to give [BH 2 (NH 3 ) 2 ][BH 4 ] …”

Synthesis of ammonia borane for hydrogen storage applications

“…[7][8][9] In a classic series of papers from Parry's laboratory in the 1950s, the structure of DADB was finally proven to be the species containing the boronium cation and borohydride ion pair, which is species II in the scheme shown above. [10][11][12][13][14][15][16] It was during these experimental studies that serendipity played a role in providing AB. Sheldon Shore had added NH 4 Cl to the DADB in an attempt to prepare the corresponding chloride salt [NH 3 BH 2 NH 3 ] + [Cl] À , eqn (1), in analogy with the previous work of Schultz who showed that the addition of NH 4 Br to DADB in liquid ammonia yielded the corresponding bromide salt [NH 3 BH 2 NH 3 ] + [Br] À , eqn (2).…”

Hydrogen Liberation from Gaseous 2-Bora-1,3-diazacycloalkanium Cations

“…Many years ago Shore et al showed that the reaction of gaseous ammonia with diborane produces the diammoniate of diborane (H 3 N–BH 2 –NH 3 + BH 4 – ) instead of the simple Lewis acid–base adduct H 3 N–BH 3 . − Longer oligomers consisting of sp 3 boron bonded to sp 3 nitrogen have been synthesized, , and a variety of conditions also produce other diaminoboranes containing only sp 3 centers. − In the present work, reaction of linear aliphatic α,ω-diamines with borane yields product mixtures from which the positive ions 3 - 12 can be isolated by ESI mass spectrometry and their infrared spectra in the gas phase examined using the IRMPD technique.…”

“…More than half a century ago, Kelly and Edwards reported preparation of the diamine-borane 1 ( n = 0) from diborane and 1,2-diaminoethane . At the time, they inquired whether neutral bis -adduct 1 represents the true structure, or whether it consists of an ionic solid, 2 , the borohydride salt of the 5-member cyclic cation (analogous to the interconversion of ammonia borane with the diammoniate of diborane), as shown in eq . − They subsequently concluded that it does have the covalent structure 1 , which was later confirmed by single crystal X-ray diffraction and, more recently, by Neiner et al using X-ray powder diffraction …”