Ammonium borane

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Structural formula
Structural formula of ammonia-borane
General
Surname Ammonium borane
other names

Borazan

Molecular formula BH 6 N
Brief description

white to beige crystalline powder with an ammonia-like odor

External identifiers / databases
CAS number 13774-81-7
EC number 642-983-4
ECHA InfoCard 100.170.890
PubChem 6332567
Wikidata Q424486
properties
Molar mass 30.87 g mol −1
Physical state

firmly

Melting point

97.61 ° C (decomposition begins at 68 ° C)

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Amminborane is a chemical compound from the borane group .

Extraction and presentation

The reaction of diborane with liquid ammonia at −78 ° C mainly gives its diammonium salt [H 2 B (NH 3 ) 2 ] + (BH 4 ) - . If, however, the THF complex of borane is used instead of diborane, ammonium borane results.

properties

Ammonium borane has a structure similar to that of ethane , the large difference in the melting point of the two compounds being due to the strongly polar nature of ammonium borane. The BN distance is 1.58 Å, the BH distance is 1.15 Å and the NH distance is 0.96 Å.

Resonance structure of ammonium borane

use

Ammonium borane is being discussed as a storage substance for hydrogen gas as a fuel for vehicles. The hydrogen can be released by heating, whereby it first decomposes into (NH 2 BH 2 ) n and then into (NHBH) n . Its hydrogen storage density is higher than liquid hydrogen.

Ammonium borane is also used in organic syntheses as a stable variant of diborane.

Individual evidence

  1. Ammonia borane (GfsChemicals) ( Memento of the original from January 17, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 43 kB)  @1@ 2Template: Webachiv / IABot / www.gfschemicals.com
  2. a b Datasheet Borane-ammonia complex from Sigma-Aldrich , accessed on May 9, 2017 ( PDF ).
  3. SG Shore, KW Boeddeker: Large Scale Synthesis of H 2 B (NH 3 ) 2 + BH 4 - and H 3 NBH 3 . In: Inorganic Chemistry . 1964, 3, pp. 914-15, doi : 10.1021 / ic50016a038 .
  4. ^ Rebirth for Hydrogen Tanks (Technology Review) .
  5. ^ " Hydrogen gets on board ", Maciej Gutowski and Tom Autrey, Royal Society of Chemistry.
  6. ^ Frances H. Stephens, Vincent Pons, R. Tom Baker: Ammonia borane: the hydrogen source par excellence? . In: Dalton Transactions , 2007, pp. 2613-2626, doi : 10.1039 / b703053c .
  7. ^ GC Andrews: Borane Ammonia . In Encyclopedia of Reagents for Organic Synthesis , 2004, doi : 10.1002 / 047084289X.rb238.pub2 .