Ferricyanide is the name for the anionFe(CN)63−. Its systematic name is '''hexacyanoferrate(III)''' ion. 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)63− consists of an Fe3+ center bound in octahedral geometry to six cyanideligands. The complex has Ohsymmetry group|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:
- Fe(CN)63− + e− → Fe(CN)64−
This couple is a standard in electrochemistry.
Treatment of ferricyanide with ferrous salts affords the brilliant, long-lasting pigment Prussian Blue, the color of blueprints.
