Iron(II) bromide

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Iron(II) bromide
Iron(II) bromide
IUPAC name
Iron(II) bromide
Other names
Ferrous bromide
7789-46-0 YesY
ChemSpider 74218 YesY
Jmol-3D images Image
PubChem 659170
Molar mass 215.65 g mol−1
Appearance yellow-brown solid
Density 4.63 g cm−3, solid
Melting point 684 °C (1,263 °F; 957 K)
Boiling point 934 °C (1,713 °F; 1,207 K)
Solubility in other solvents THF, methanol, ethanol
Crystal structure Rhombohedral, hP3, SpaceGroup = P-3m1, No. 164
Main hazards none
R-phrases R20 R36/37/38
S-phrases S26 S36
Related compounds
Other anions
Iron(II) chloride
Other cations
iron(III) bromide
Related compounds
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(II) bromide is the chemical compound with the chemical formula FeBr2. This brownish-colored solid is a useful synthetic intermediate; for example it is employed to insert Fe(II) into porphyrins.


Like most metal halides, FeBr2 adopts a polymeric structure consisting of isolated metal centers cross-linked with halides. It crystallizes with the CdI2 structure, featuring close-packed layers of bromide ions, between which are located Fe(II) ions in octahedral holes.[1] The packing of the halides is slightly different from that for FeCl2, which adopts the CdCl2 motif. FeBr2 also forms hydrates.


FeBr2 is conveniently synthesized using a methanol solution of concentrated hydrobromic acid. Addition with Fe gives the methanol solvate [Fe(MeOH)6]Br2 together with hydrogen gas. Heating the methanol complex in a vacuum at ca. 160 °C gives pure FeBr2.[2]

Iron(II) bromide cannot be formed by the reaction of iron and bromine, because that reaction would produce ferric bromide.


FeBr2 reacts with 2 equivalents of (C2H5)4NBr to give [(C2H5)4N]2FeBr4.[3]

FeBr2 reacts with bromide and bromine to form the intensely colored, mixed-valence species [FeBr3Br9].[4]

FeBr2 is a weak reducing agent, as are all ferrous compounds.


  1. ^ Haberecht, J.; Borrmann, H.; Kniep, R. "Refinement of the Crystal Structure of Iron Dibromide, FeBr2 Zeitschrift für Kristallographie - New Crystal Structures (2001), volume 216, page 510.
  2. ^ G. Winter, "Iron(II) Halides" in "Inorganic Syntheses" 1973, volume 14, pages 101-104.
  3. ^ N. S. Gill, F.. B. Taylor Inorganic Syntheses 1967, volume 9, page 136-142.
  4. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5