Ferricyanide

Summary

Ferricyanide
HexacyanidoferratIII 2.svg
Ferricyanide-3D.png
Names
IUPAC name
iron(3+) hexacyanide
Systematic IUPAC name
hexacyanidoferrate(III)
Other names
ferric hexacyanide; hexacyanidoferrate(3−); hexacyanoferrate(III)
Identifiers
  • 13408-62-3 checkY
3D model (JSmol)
  • Interactive image
ChEBI
  • CHEBI:5020
ChemSpider
  • 388349 checkY
KEGG
  • C00324
  • 439210
  • DTXSID70894190 Edit this at Wikidata
  • InChI=1S/6CN.Fe/c6*1-2;/q6*-1;+3
    Key: YAGKRVSRTSUGEY-UHFFFAOYSA-N
  • N#C[Fe-3](C#N)(C#N)(C#N)(C#N)C#N
Properties
[Fe(CN)6]3−
Related compounds
Other cations
Hexacyanonickelate(III)
Related compounds
Ferrocyanide
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

Ferricyanide is the anion [Fe(CN)6]3−. It is also called hexacyanoferrate(III) and in rare, but systematic nomenclature, hexacyanidoferrate(III). The most common salt of this anion is potassium ferricyanide, a red crystalline material that is used as an oxidant in organic chemistry.[1]

Properties

[Fe(CN)6]3− consists of a Fe3+ center bound in octahedral geometry to six cyanide ligands. The complex has Oh symmetry. The iron is low spin and easily reduced to the related ferrocyanide ion [Fe(CN)6]4−, which is a ferrous (Fe2+) derivative. This redox couple is reversible and entails no making or breaking of Fe–C bonds:

[Fe(CN)6]3− + e ⇌ [Fe(CN)6]4−

This redox couple is a standard in electrochemistry.

Compared to main group cyanides like potassium cyanide, ferricyanides are much less toxic because of the strong bond between the cyanide ion (CN ) and the Fe3+. They do react with mineral acids, however, to release highly toxic hydrogen cyanide gas.

Uses

Treatment of ferricyanide with iron(II) salts affords the brilliant, long-lasting pigment Prussian blue, the traditional color of blueprints.

See also

References

  1. ^ Gail, E.; Gos, S.; Kulzer, R.; Lorösch, J.; Rubo, A.; Sauer, M.; Kellens, R.; Reddy, J.; Steier, N. "Cyano Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub3.