Copper(I) bromide

Copper(I) bromide
Sample of copper(I) bromide
Sample of copper(I) bromide
Structure of CuBr
Structure of CuBr
Names
Other names
Cuprous bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.210 Edit this at Wikidata
UNII
  • InChI=1S/BrH.Cu/h1H;/q;+1/p-1 checkY
    Key: NKNDPYCGAZPOFS-UHFFFAOYSA-M checkY
  • InChI=1/BrH.Cu/h1H;/q;+1/p-1
    Key: NKNDPYCGAZPOFS-REWHXWOFAY
  • Br[Cu]
Properties
CuBr
Molar mass 143.450 g·mol−1
Appearance white powder
Density 4.98 g/cm3
Melting point 483 °C (901 °F; 756 K)
Boiling point 1,345 °C (2,453 °F; 1,618 K)
0.0012 g/100 g (20 °C (68 °F))
6.27×10−9
Band gap 1.00 eV
−49.0×10−6 cm3/mol
2.116[citation needed]
Structure
Tetragonal [129]
P4/nmm
4/mmm
a = 3.85 Å, b = 3.85 Å, c = 6.04 Å
α = 90°, β = 90°, γ = 90°
89.78 Å3
2
Tetrahedral at Cu1+
Thermochemistry
54.7 J⋅mol−1⋅K−1
96.1 J⋅mol−1⋅K−1
−104.6 kJ⋅mol−1
−100.8 kJ⋅mol−1
Enthalpy of fusion (ΔfH⦵fus)
 5.1 kJ⋅mol−1
Hazards
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation markGHS09: Environmental hazard
Danger
H302+H312, H315, H318, H410
P264, P270, P273, P280, P301+P312+P330, P302+P352+P312, P305+P351+P338+P310, P332+P313, P362, P391, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 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
2
0
0
1 mg/m3 (TWA)
Lethal dose or concentration (LD, LC):
  • 336 mg/kg (rat, oral)
  • 1224 mg/kg (rat, dermal)
NIOSH (US health exposure limits):
PEL (Permissible)
 1 mg/m3 (TWA, as Cu)
REL (Recommended)
 1 mg/m3 (TWA, as Cu)
IDLH (Immediate danger)
 100 mg/m3 (as Cu)
Related compounds
Other anions
Other cations
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkYX markN ?)

Copper(I) bromide is the chemical compound with the formula CuBr. This white diamagnetic solid adopts a polymeric structure akin to that for zinc sulfide. The compound is widely used in the synthesis of organic compounds and as a lasing medium in copper bromide lasers.

Properties

The compound is white, although samples are often colored due to the presence of copper(II) impurities.[page needed] The copper(I) ion also oxidizes easily in air. CuBr is insoluble in most solvents due to its polymeric structure, which features four-coordinated, tetrahedral Cu centers interconnected by bromide ligands (ZnS structure).

Thermal excitation of copper(I) bromide vapour yields a blue-violet emission which is of greater saturation than known copper(I) chloride emission. Copper(I) bromide is hence an advantageous emitter in pyrotechnic flames.

Preparation

It is commonly prepared by the reduction of cupric salts with sulfite in the presence of bromide. For example, the reduction of copper(II) bromide with sulfite yields copper(I) bromide and hydrogen bromide:

2 CuBr2 + H2O + SO2−3 → 2 CuBr + SO2−4 + 2 HBr

Applications in organic chemistry

In the Sandmeyer reaction, CuBr is employed to convert diazonium salts into the corresponding aryl bromides:

ArN+2 + CuBr → ArBr + N2 + Cu+

The aforementioned complex CuBr(S(CH3)2) is widely used to generate organocopper reagents. Related CuBr complexes are catalysts for atom transfer radical polymerization (ATRP) and copper-catalyzed cross dehydrogenative couplings (CDCs).[citation needed]

Reactions

Upon treatment with Lewis bases, CuBr converts to molecular adducts. For example, with dimethyl sulfide (S(CH3)2), the colorless complex is formed:

CuBr + S(CH3)2 → CuBr(S(CH3)2)

In this coordination complex, the copper is two-coordinate, with a linear geometry. Other soft ligands afford related complexes. For example, triphenylphosphine (P(C6H5)3) gives CuBr(P(C6H5)3), although this species has a more complex structure.[citation needed]

References

  1. 1 2 Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton, Florida: CRC Press. pp. 4–59, 4–127, 5–11, 5–177, 6–156. ISBN 9781498754293.
  2. 1 2 "Materials Data on CuBr". next-gen.materialsproject.org. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA: LBNL Materials Project. 2020-07-16. doi:10.17188/1199082. OSTI 1199082. mp-22917, DOE Contract Number AC02-05CH11231.
  3. 1 2 Sigma-Aldrich Co., Copper(I) bromide. Retrieved on 21 July 2026.
  4. 1 2 "SDS - Copper(I) bromide". www.fishersci.com. Revision 5. ThermoFisher Scientific. 21 December 2025 [16 November 2010]. Retrieved 22 July 2026.
  5. ↑ "NIOSH Pocket Guide to Chemical Hazards".
  6. ↑ Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils (ed.), Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, ISBN 0-12-352651-5
  7. ↑ Koch, E.-C. (2015). "Spectral Investigation and Color Properties of Copper(I) Halides CuX (X=F, Cl, Br, I) in Pyrotechnic Combustion Flames". Propellants Explos. Pyrotech. 40 (6): 798–802. doi:10.1002/prep.201500231.
  8. 1 2 This report gives a procedure for generating CuBr: Hartwell, Jonathan L. (1955). "o-Chlorobromobenzene". Organic Syntheses; Collected Volumes, vol. 3, p. 185.
  9. 1 2 Jarowicki, K.; Kocienski, P. J.; Qun, L. "1,2-Metallate Rearrangement: (Z)-4-(2-Propenyl)-3-Octen-1-ol". Organic Syntheses. 79: 11; Collected Volumes, vol. 10, p. 662.