Gold(I) cyanide

Gold(I) cyanide is the inorganic compound with the chemical formula AuCN. It is the binary cyanide of gold(I). It is an odourless, tasteless yellow solid.^[4] Wet gold(I) cyanide is unstable to light and will become greenish.^[4] Gold(I) cyanide itself is only of academic interest, but its derivative dicyanoaurate is an intermediate in gold cyanidation, the extraction of gold from its ores.^[5]

Gold(I) cyanide

Names
Other names Gold monocyanide
Identifiers
CAS Number	506-65-0 Y[PubChem]
3D model (JSmol)	Interactive image
ChemSpider	61479
ECHA InfoCard	100.007.318
EC Number	208-049-1
PubChem CID	68172
CompTox Dashboard (EPA)	DTXSID1060136
InChI InChI=1S/CN.Au/c1-2;/q-1;+1 Key: IZLAVFWQHMDDGK-UHFFFAOYSA-N
SMILES [Au+].[C-]#N
Properties
Chemical formula	CAuN
Molar mass	222.985 g·mol−1
Appearance	dark yellow powder[1]
Density	7.12 g·cm−3[2]
Solubility in water	insoluble
Structure
Crystal structure	hexagonal
Space group	P6mm (No. 183)
Lattice constant	a = 340 pm, c = 509 pm[2]
Hazards
GHS labelling:[3]
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H410
Related compounds
Other cations	Copper(I) cyanide Silver cyanide
Related compounds	Gold(III) cyanide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

Solid gold(I) cyanide precipitates upon reaction of potassium dicyanoaurate with hydrochloric acid:

K[Au(CN)₂] + HCl → AuCN + HCN + KCl

It can also be produced by the reaction of gold(III) chloride and potassium cyanide.^[2]

Reactions

The solid dissolves to form water-soluble adducts with a variety of ligands: cyanides, hydroxide, ammonia, thiosulfate and hydrosulfide.^[2]

Like most gold compounds, it converts to metallic gold upon heating.^{[citation needed]}

Structure

Gold(I) cyanide's is a coordination polymer consisting of linear chains of AuCN such that each Au(I) center is bonded to carbon and nitrogen. The structure is hexagonal with the lattice parameters a = 3.40 Å and c = 5.09 Å.^[2] T^[6]