Ferricyanide
Names | |
---|---|
IUPAC name
iron(3+) hexacyanide | |
Systematic IUPAC name
hexacyanidoferrate(III) | |
Other names
ferric hexacyanide; hexacyanidoferrate(3-); hexacyanoferrate(III) | |
Identifiers | |
3D model (Jmol) | Interactive image |
PubChem | 439210 |
| |
Properties | |
[Fe(CN)6]3− | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
verify (what is ?) | |
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 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.
Uses
Treatment of ferricyanide with ferrous salts affords the brilliant, long-lasting pigment Prussian blue, the traditional color of blueprints.
References
- ↑ Gail, E.; Gos, S.; Kulzer, R.; Lorösch, J.; Rubo, A.; Sauer, M.; Kellens, R.; Reddy, J.; Steier, N.; Hasenpusch, W. (October 2011). "Cyano Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub3.
See also
Salts and covalent derivatives of the cyanide ion | |||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
HCN | He | ||||||||||||||||||
LiCN | Be(CN)2 | B | C | NH4CN | OCN−, -NCO |
FCN | Ne | ||||||||||||
NaCN | Mg(CN)2 | Al(CN)3 | SiCN | P(CN)3 | SCN−, -NCS, (SCN)2, S(CN)2 |
ClCN | Ar | ||||||||||||
KCN | Ca(CN)2 | Sc(CN)3 | Ti(CN)4 | VO(CN)3 | Cr(CN)3 | Mn(CN)2 | Fe(CN)3, Fe(CN)64+, Fe(CN)63+ |
Co(CN)2, Co(CN)3 |
Ni(CN)2 Ni(CN)42− |
CuCN | Zn(CN)2 | Ga(CN)3 | Ge | As(CN)3 | SeCN− (SeCN)2 Se(CN)2 |
BrCN | Kr | ||
RbCN | Sr(CN)2 | Y(CN)3 | Zr(CN)4 | Nb | Mo | Tc | Ru | Rh | Pd(CN)2 | AgCN | Cd(CN)2 | In(CN)3 | Sn | Sb | Te(CN)2, Te(CN)4 |
ICN | XeCN | ||
CsCN | Ba(CN)2 | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg2(CN)2, Hg(CN)2 |
TlCN | Pb(CN)2 | Bi(CN)3 | Po | At | Rn | |||
Fr | Ra | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og | |||
↓ | |||||||||||||||||||
La | Ce(CN)3, Ce(CN)4 |
Pr | Nd | Pm | Sm | Eu | Gd(CN)3 | Tb | Dy | Ho | Er | Tm | Yb | Lu | |||||
Ac | Th | Pa | UO2(CN)2 | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr |