Names | |
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IUPAC name
iron(3+) hexacyanide
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Systematic IUPAC name
hexacyanidoferrate(III) | |
Other names
ferric hexacyanide; hexacyanidoferrate(3−); hexacyanoferrate(III)
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Identifiers | |
3D model (
JSmol)
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ChEBI | |
ChemSpider | |
KEGG | |
PubChem
CID
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CompTox Dashboard (
EPA)
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Properties | |
[Fe(CN)63− | |
Related compounds | |
Other
cations
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Hexacyanonickelate(III) |
Related compounds
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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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Ferricyanide is the anion [Fe(CN)63−. 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]
[Fe(CN)63− 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)64−, which is a ferrous (Fe2+) derivative. This redox couple is reversible and entails no making or breaking of Fe–C bonds:
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.
Treatment of ferricyanide with iron(II) salts affords the brilliant, long-lasting pigment Prussian blue, the traditional color of blueprints.