Beryllium bromide

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 Be centres.[3]

Beryllium bromide
Names
IUPAC name
Beryllium bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.196
EC Number
  • 232-115-9
UNII
  • InChI=1S/Be.2BrH/h;2*1H/q+2;;/p-2 Y
    Key: PBKYCFJFZMEFRS-UHFFFAOYSA-L Y
  • 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:
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)
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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Infobox references

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 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. 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. NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH).
  3. Crystal modifications of Beryllium dihalides BeCl2, BeBr2, and BeI2 Troyanov, S. I. Zhurnal Neorganicheskoi Khimii (2000), 45(10), 1619-1624.
  4. Troyanov, S.I. (2000). "Crystal Modifications of Beryllium Dihalides BeCl2, BeBr2 and BeI2". Zhurnal Neorganicheskoi Khimii. 45: 1619-1624.
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