Chemistry:Beryllium bromide

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Beryllium bromide
Beryllium bromide.svg
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Names
IUPAC name
Beryllium bromide
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 232-115-9
UNII
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
Main hazards see Berylliosis
GHS pictograms GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
GHS Signal word Danger
H350i, H330, H301, H372, H319, H335, H315, H317, H411
P260, P301+310, P304+340, P305+351+338, P320, P330, P405, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 4: Very short exposure could cause death or major residual injury. E.g. VX gasReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
4
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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Infobox references
Tracking categories (test):

Beryllium bromide is the chemical compound with the formula BeBr2. It is very hygroscopic and dissolves well in water. The compound is a polymer with tetrahedral coordinated Be centres.[3]

Preparation and reactions

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

Be + Br2 → BeBr2

Beryllium bromide is also formed when treating beryllium oxide with hydrobromic acid:

BeO + 2 HBr → BeBr2 + H2O

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

Structure

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.[4]

Safety

Beryllium compounds are toxic if inhaled or ingested.

References

  1. 1.0 1.1 1.2 Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, pp. 61–62, ISBN 0-8493-8671-3, https://books.google.com/books?id=0fT4wfhF1AsC&q=%22beryllium+bromide%22+properties&pg=PA61, retrieved 2007-12-10 
  2. 2.0 2.1 2.2 NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0054.html. 
  3. Crystal modifications of Beryllium dihalides BeCl2, BeBr2, and BeI2 Troyanov, S. I. Zhurnal Neorganicheskoi Khimii (2000), 45(10), 1619-1624.
  4. 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.