Cobalt(II) cyanide

Cobalt(II) cyanide

Names
IUPAC name Cobalt(II) cyanide
Other names cobaltous cyanide
Identifiers
CAS Number	542-84-7 Y 20427-11-6 (dihydrate) N 26292-31-9 (trihydrate) N
ChemSpider	61631 Y
Jmol 3D model	Interactive image
PubChem	68336
InChI InChI=1S/2CN.Co/c2*1-2;/q2*-1;+2 Y Key: CWZOMTYLSNXUEL-UHFFFAOYSA-N Y InChI=1/2CN.Co/c2*1-2;/q2*-1;+2 Key: CWZOMTYLSNXUEL-UHFFFAOYAR
SMILES [Co+2].[C-]#N.[C-]#N
Properties
Chemical formula	Co(CN)2
Molar mass	110.968 g/mol (anhydrous) 147.00 g/mol (dihydrate) 165.02 g/mol (trihydrate)
Appearance	deep-blue powder hygroscopic (anhydrous) reddish-brown powder (dihydrate)
Density	1.872 g/cm3 (anhydrous)
Melting point	280 °C (536 °F; 553 K) (anhydrous)
Solubility in water	insoluble
Solubility	dihydrate degraded with dissolution by NaCN, KCN, NH4OH, HCl
Vapor pressure	{{{value}}}
Related compounds
Other anions	Cadmium chloride, Cadmium iodide
Other cations	Zinc cyanide, Calcium cyanide, Magnesium cyanide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Cobalt(II) cyanide is the inorganic compound with the formula Co(CN)₂. It is coordination polymer that has attracted intermittent attention over many years in the area of inorganic synthesis and homogeneous catalysis.

Uses

Cobalt(II) cyanide has been used as a precursor to cobalt carbonyl.

Preparation

The trihydrate salt is obtained as a reddish brown precipitate by adding potassium cyanide to a cobalt salt solution.:

CoCl₂(H₂O)₆ + 2 KCN → Co(CN)₂ + 2 KCl + 6 H₂O

Hydrated Co(CN)₂ dissolves in the presence of excess potassium cyanide, forming a red solution of K₄Co(CN)₆. This material further oxidizes to yellow K₃Co(CN)₆.