Ferricyanide


Ferricyanide is the name of the anion. It is also called hexacyanoferrate and in rare, but systematic nomenclature, hexacyanidoferrate. The most common salt of this anion is potassium ferricyanide, a red crystalline material that is used as an oxidant in organic chemistry.

Properties

consists of a 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, which is a ferrous 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 and the. They do react with mineral acids, however, to release highly toxic hydrogen cyanide gas.

Uses

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