Iron(III) bromide is the chemical compound with the formula FeBr3. Also known as ferric bromide, this red-brown odorless compound is used as a Lewis acid catalyst in the halogenation of aromatic compounds. It dissolves in water to give acidic solutions.

Iron(III) bromide
Names
IUPAC name
Iron(III) bromide
Other names
Ferric bromide
Iron tribromide
tribromoiron
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.069 Edit this at Wikidata
EC Number
  • 233-089-1
UNII
  • InChI=1S/3BrH.Fe/h3*1H;/q;;;+3/p-3 checkY
    Key: FEONEKOZSGPOFN-UHFFFAOYSA-K ☒N
  • InChI=1/3BrH.Fe/h3*1H;/q;;;+3/p-3
    Key: FEONEKOZSGPOFN-DFZHHIFOAP
  • [Fe](Br)(Br)Br
Properties
FeBr3
Molar mass 295.56 g mol−1
Appearance brown solid
Odor odorless
Density 4.50 g cm−3
Melting point 200 °C (392 °F; 473 K) (decomposes)
Structure
Trigonal, hR24
R-3, No. 148
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
corrosive
GHS labelling:[1]
GHS07: Exclamation mark
Warning
H315, H319, H335
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine 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
3
0
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure, synthesis and basic properties

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FeBr3 forms a polymeric structure featuring six-coordinate, octahedral Fe centers.[2] Although inexpensively available commercially, FeBr3 can be prepared by treatment of iron metal with bromine:

2 Fe + 3 Br2 → 2 FeBr3

Above 200 °C, FeBr3 decomposes to ferrous bromide:

2FeBr3 → 2FeBr2 + Br2

Iron(III) chloride is considerably more stable, reflecting the greater oxidizing power of chlorine. FeI3 is not stable, as iron(III) will oxidize iodide ions.

Uses

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Ferric bromide is occasionally used as an oxidant in organic chemistry, e.g. for the conversion of alcohols to ketones. It is used as a Lewis acidic catalyst for bromination of aromatic compounds. For the latter applications, it is often generated in situ.[3]

See also

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References

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  1. ^ "C&L Inventory". echa.europa.eu.
  2. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  3. ^ Drapeau, Martin Pichette; Lafantaisie, Mathieu; Ollevier, Thierry (2013). "Iron(III) bromide". E-EROS Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn01568. ISBN 978-0471936237.