Gold(I) chloride

Gold(I) chloride is a compound of gold and chlorine with the chemical formula AuCl.

Gold(I) chloride
Names
IUPAC name
Gold(I) chloride
Other names
Aurous chloride
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard100.030.583 Edit this at Wikidata
UNII
  • InChI=1S/Au.ClH/h;1H/q+1;/p-1 checkY
    Key: FDWREHZXQUYJFJ-UHFFFAOYSA-M checkY
  • InChI=1/Au.ClH/h;1H/q+1;/p-1
    Key: FDWREHZXQUYJFJ-REWHXWOFAM
  • [Au]Cl
Properties
AuCl
Molar mass232.423 g/mol
Appearanceyellow solid
Density7.6 g/cm3 [1]
Melting point170 °C (338 °F; 443 K)
Boiling point298 °C (568 °F; 571 K) (decomposes)
very slightly soluble
Solubilitysoluble in HCl, HBr organic solvents
−67.0·10−6 cm3/mol
Structure
Tetragonal, tI16
I41/amd, No. 141
Hazards
NFPA 704 (fire diamond)
Safety data sheet (SDS)MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation

Gold(I) chloride is prepared by thermal decomposition of gold(III) chloride.

Reactions

Although there is a region of stability at higher temperatures at the appropriate chlorine vapor pressures, the compound is metastable at ambient conditions. When heated with water, the compound dispropotionates to metallic gold and gold(III) chloride in an autoredox reaction:

3 AuCl → 2 Au + AuCl3

At still higher temperatures, around 500 °C, all gold chlorides convert to gold. This conversion is key to the Miller process, which is widely used for the purification of gold.[2]

Reaction with potassium bromide yields potassium auric bromide and potassium chloride with separation of metallic gold:

3 AuCl + 4 KBr → KAuBr4 + 2 Au + 3 KCl

Safety

Gold(I) chloride may irritate the skin and eyes, damage kidney function, and reduce white blood cell counts.

References