Potassium hexacyanochromate(III)

Potassium hexacyanochromate(III)

Names
IUPAC name Potassium hexacyanochromate(III)
Identifiers
CAS Number	13601-11-1
3D model (JSmol)	Interactive image
ChemSpider	19988791 Y
ECHA InfoCard	100.033.694
EC Number	237-079-8
MeSH	Hexacyanochromate
PubChem CID	21123765
InChI InChI=1S/6CN.Cr.3K/c6*1-2;;;;/q;;;;;;-3;3*+1 Y Key: VOCDJOPDZZSPRQ-UHFFFAOYSA-N Y
SMILES [K+].[K+].[K+].N#C[Cr-3](C#N)(C#N)(C#N)(C#N)C#N
Properties
Chemical formula	C6CrK3N6
Molar mass	325.40 g·mol−1
Appearance	Vivid, yellow, opaque crystals
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Potassium hexacyanochromate(III) is a coordination compound with the formula K₃[Cr(CN)₆]. It consists of three potassium cations and a central hexacyanometallate with [Cr(CN)₆]³⁻ anion. It is a yellow, air-stable, paramagnetic solid. It is not stable at higher temperatures, forming chromium(III) hydroxide precipitate.

The salt is prepared by treating chromium trioxide, dissolved in concentrated hydrochloric acid, with ethanol in a redox reaction. Following the solution is evaporated to dryness. The residue is dissolved in a boiling solution of KCN. The evaporation is repeated, but not till dryness. The concentrated solution is left in the cold to sulphur.

The Cr(II) derivative is unusual and has been little studied.