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Beryllium bromide

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Beryllium bromide
Names
IUPAC name
Beryllium bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.196 Edit this at Wikidata
EC Number
  • 232-115-9
UNII
  • InChI=1S/Be.2BrH/h;2*1H/q+2;;/p-2 checkY
    Key: PBKYCFJFZMEFRS-UHFFFAOYSA-L checkY
  • InChI=1/Be.2BrH/h;2*1H/q+2;;/p-2
    Key: PBKYCFJFZMEFRS-NUQVWONBAJ
  • Br[Be-2](Br)([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1([Br+]1)[Br+][Be-2]1(Br)Br
Properties
BeBr2
Molar mass 168.820 g/mol
Appearance colorless white crystals
Density 3.465 g/cm3 (20 °C)
Melting point 508 °C (946 °F; 781 K)sublimes at 473 °C (883 °F; 746 K)
Boiling point 520 °C (968 °F; 793 K)[1]
Highly[1]
Solubility soluble in ethanol, diethyl ether, pyridine
insoluble in benzene
Structure
Orthorhombic
Thermochemistry
0.4111 J/g K
9.5395 J/K
-2.094 kJ/g
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 see Berylliosis
GHS labelling:
GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
Danger
H301, H315, H317, H319, H330, H335, H350i, H372, H411
P260, P301+P310, P304+P340, P305+P351+P338, P320, P330, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
0
0
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.002 mg/m3
C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be)[2]
REL (Recommended)
 Ca C 0.0005 mg/m3 (as Be)[2]
IDLH (Immediate danger)
 Ca [4 mg/m3 (as Be)][2]
Related compounds
Other anions
 Beryllium fluoride
Beryllium chloride
Beryllium iodide
Other cations
 Magnesium bromide
Calcium bromide
Strontium bromide
Barium bromide
Radium bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Beryllium bromide is the chemical compound with the formula BeBr2. It is very hygroscopic and dissolves well in water. The Be2+ cation, which is relevant to BeBr2, is characterized by the highest known charge density (Z/r = 6.45), making it one of the hardest cations and a very strong Lewis acid.[3]

Preparation and reactions

[edit]

It can be prepared by reacting beryllium metal with elemental bromine at temperatures of 500 °C to 700 °C:[1]

Be + Br2 → BeBr2

When the oxidation is conducted on an ether suspension, one obtains colorless dietherate:[4]

Be + Br2 + 2 O(C2H5)2 → BeBr2(O(C2H5)2)2

The same dietherate is obtained by suspending beryllium dibromide in diethyl ether:[5]

BeBr2 2 O(C2H5)2 → BeBr2(O(C2H5)2)2

This ether ligand can be displaced by other Lewis bases.is ether ligand can be displaced by other Lewis bases.

Beryllium bromide hydrolyzes slowly in water: BeBr2 + 2 H2O → 2 HBr + Be(OH)2

Structure

[edit]

Two forms (polymorphs) of BeBr2 are known. Both structures consist of tetrahedral Be2+ centers interconnected by doubly bridging bromide ligands. One form consist of edge-sharing polytetrahedra. The other form resembles zinc iodide with interconnected adamantane-like cages.[6][7]

Safety

[edit]

Beryllium compounds are toxic if inhaled or ingested.

References

[edit]
  1. ^ a b c Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, pp. 61–62, ISBN 0-8493-8671-3, retrieved 2007-12-10
  2. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ Buchner, M. R. (2017-01-01), "Beryllium Chemistry", Reference Module in Chemistry, Molecular Sciences and Chemical Engineering, Elsevier, ISBN 978-0-12-409547-2, retrieved 2022-10-27
  4. ^ Paparo, Albert; Jones, Cameron (2019-02-01). "Beryllium Halide Complexes Incorporating Neutral or Anionic Ligands: Potential Precursors for Beryllium Chemistry". Chemistry: An Asian Journal. 14 (3): 486–490. doi:10.1002/asia.201801800. ISSN 1861-4728. PMID 30604490. S2CID 58632466.
  5. ^ Paparo, Albert; Jones, Cameron (2019-02-01). "Beryllium Halide Complexes Incorporating Neutral or Anionic Ligands: Potential Precursors for Beryllium Chemistry". Chemistry: An Asian Journal. 14 (3): 486–490. doi:10.1002/asia.201801800. ISSN 1861-4728. PMID 30604490. S2CID 58632466.
  6. ^ Buchner, Magnus R.; Dankert, Fabian; Spang, Nils; Pielnhofer, Florian; von Hänisch, Carsten (2020). "A Second Modification of Beryllium Bromide: β-BeBr2". Inorganic Chemistry. 59 (23): 16783–16788. doi:10.1021/acs.inorgchem.0c02832. PMID 33185106. S2CID 226850424.
  7. ^ Troyanov, S. I. (2000). "Crystal Modifications of Beryllium Dihalides BeCl2, BeBr2, and BeI2". Zhurnal Neorganicheskoi Khimii. 45: 1619-1624.
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