Copper(I) bromide

Source: Wikipedia, the free encyclopedia.
Copper(I) bromide
Sample of copper(I) bromide
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 143.45 g/mol
Appearance white powder (see text)
Density 4.71 g/cm3, solid
Melting point 492 °C (918 °F; 765 K)
Boiling point 1,345 °C (2,453 °F; 1,618 K)
insoluble;
slightly soluble in cold water
6.27×10−9[1]
Solubility soluble in
ammonium hydroxide, acetonitrile
negligible in acetone, sulfuric acid
−49.0×10−6 cm3/mol
2.116
1.46 D
Hazards
Flash point Non-flammable
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1 mg/m3 (as Cu)[2]
REL (Recommended)
TWA 1 mg/m3 (as Cu)[2]
IDLH
(Immediate danger)
TWA 100 mg/m3 (as Cu)[2]
Related compounds
Other anions
Copper(I) chloride
Copper(I) iodide
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 checkY☒N ?)

Copper(I) bromide is the

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.

Preparation, basic properties, structure

The compound is white, although samples are often colored due to the presence of copper(II) impurities.[3] The copper(I) ion also oxidizes easily in air. It is commonly prepared by the reduction of cupric salts with sulfite in the presence of bromide.[4] 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

CuBr is insoluble in most solvents due to its polymeric structure, which features four-coordinated, tetrahedral Cu centers interconnected by bromide ligands (ZnS structure). Upon treatment with

Lewis bases, CuBr converts to molecular adducts. For example, with dimethyl sulfide, the colorless complex is formed:[5]

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 gives CuBr(P(C6H5)3), although this species has a more complex structure. Thermal excitation of copper(I) bromide vapour yields a blue-violet emission which is of greater

pyrotechnic
flames.

Applications in organic chemistry

In the

aryl bromides:[4]

ArN+
2
+ CuBr → ArBr + N2 + Cu+

The aforementioned complex CuBr(S(CH3)2) is widely used to generate

atom transfer radical polymerization
and copper-catalyzed cross-dehydrogenative couplings (CDC).

See also

Copper(II) bromide

References

  1. .
  2. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
  3. .
  4. ^ a b This report gives a procedure for generating CuBr: Hartwell, Jonathan L. (1955). "o-Chlorobromobenzene". Organic Syntheses; Collected Volumes, vol. 3, p. 185.
  5. ^ a b 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.
  6. .

External links