Iron(III) bromide

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Iron(III) bromide
Bismuth-triiodide-layer-3D-balls.png
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YBr3structure.jpg
Names
IUPAC name
Iron(III) bromide
Other names
Ferric bromide
Iron tribromide
tribromoiron
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.069
UNII
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
Main hazards corrosive
R-phrases (outdated) R36/37/38
S-phrases (outdated) S26 S37/39
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
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

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 with water to give acidic solutions.

Structure, synthesis and basic properties[edit]

FeBr3 forms a polymeric structure featuring six-coordinate, octahedral Fe centers.[1] 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[edit]

Ferric bromide is occasional use 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.[2]

See also[edit]

References[edit]

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