|Systematic IUPAC name
ferric hexacyanide; hexacyanidoferrate(3-); hexacyanoferrate(III)
3D model (JSmol)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
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.
[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−
Compared to normal cyanides like potassium cyanide, ferricyanides are much less toxic because of the tight hold of the CN− to the Fe3+. They do react with mineral acids, however, to release highly toxic hydrogen cyanide gas.