Sodium tetrachloroaurate

Sodium tetrachloroaurate is an inorganic compound with the chemical formula NaAuCl₄. It is composed of the ions Na⁺ and AuCl₄⁻. It exists in the anhydrous and dihydrate states. At room temperature, it exists as a golden-orange solid. The anhydrous and dihydrate forms are available commercially.^[1]

Sodium tetrachloroaurate

__ Na+      __ Au3+      __ Cl−
Names
IUPAC name Sodium tetrachloroaurate(III)
Other names Sodium gold chloride, yellow gold chloride
Identifiers
CAS Number	(anhydrous), 13874-02-7 (dihyrate) 15189-51-2 (anhydrous), 13874-02-7 (dihyrate) Y
3D model (JSmol)	Interactive image
ChemSpider	25247
ECHA InfoCard	100.035.659
EC Number	239-241-3
PubChem CID	27127
UNII	7FT6QUT299 Y
CompTox Dashboard (EPA)	DTXSID20934358
InChI InChI=1S/Au.4ClH.Na/h;4*1H;/q+3;;;;;+1/p-4
SMILES [Na+].Cl[Au-](Cl)(Cl)Cl
Properties
Chemical formula	NaAuCl4
Molar mass	361.756 g/mol
Appearance	Orange powder
Density	3.81 g cm−3[2]
Solubility in water	anhydrous: 139g/100ml (10°C) 151g/100ml (20°C) 900g/100ml (60°C)[3]
Solubility	Sparingly soluble in diethyl ether,[4] soluble in alcohol, ether[3]
Hazards[5]
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P330, P332+P313, P333+P313, P337+P313, P363, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

The conventional method of preparation of sodium tetrachloroaurate involves the addition of tetrachloroauric acid solution to sodium chloride or sodium carbonate to form a mixture. The mixture is stirred at 100 °C, and then subjected to evaporation, cooling, crystallization, and drying to obtain the orange crystals of sodium tetrachloroaurate.^[4][6]

H[AuCl₄] + NaCl → Na[AuCl₄] + HCl

2 H[AuCl₄] + Na₂CO₃ → 2 Na[AuCl₄] + H₂O + CO₂

However, more efficient preparation methods have been discovered recently. These are the addition of gold with sodium oxy-halogen salts and hydrochloric acid.^[6]

Uses

It is used in a wide range of applications. For example, it is used as a catalyst for the hydrochlorination of acetylene, or the oxidation of sulfides.^[4]