Gold(III) sulfide

Gold(III) sulfide or auric sulfide is an inorganic compound with the formula Au₂S₃. Auric sulfide has been described as a black and amorphous solid.^[1] Only the amorphous phase has been produced, and the only evidence of existence is based on thermal analysis.

Gold(III) sulfide

Names
IUPAC name Gold(III) sulfide
Other names Auric sulfide, Gold trisulfide, Digold trisulfide
Identifiers
CAS Number	1303-61-3
3D model (JSmol)	Interactive image
ChemSpider	4953696
ECHA InfoCard	100.013.750
EC Number	215-124-2
PubChem CID	6451223
UNII	9VE32L584P
CompTox Dashboard (EPA)	DTXSID80926673
InChI InChI=1S/2Au.3S/q2*+3;3*-2 Key: WAUKTSZWNLNUDT-UHFFFAOYSA-N
SMILES [S-2].[S-2].[S-2].[Au+3].[Au+3]
Properties
Chemical formula	Au2S3
Molar mass	490.11 g·mol−1
Appearance	Black powder
Density	8.750 g/cm3
Solubility in water	Insoluble
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, 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

Claims

Early investigations claimed to prepare auric sulfide by the reaction of lithium tetrachloroaurate with hydrogen sulfide:

2 Li[AuCl₄] + 3 H₂S → Au₂S₃ + 2 LiCl + 6 HCl

Similar preparations via chloroauric acid, auric chloride, or gold(III) sulfate a claimed proceed in anhydrous solvents, but water evinces a redox decomposition into metallic gold in sulfuric acid:^[2][3][1]

8 Au³⁺ + 3 S²⁻ + 12 H₂O → 8 Au + 3 H₂SO₄ + 18 H⁺

Conversely, it is claimed that cyclo-octasulfur reduces gold(III) sulfate to a mixture of gold sulfides and sulfur oxides:^[1]

Au₂(SO₄)₃ + S₈ → Au₂S₃ + Au₂S + 4 SO₃ + 6 SO₂

Auric sulfide has also been claimed as the product when auric acetate is sonicated with cyclo-octasulfur in decalin.^[3]

Auric sulfide is claimed to react with nitric acid as well sodium cyanide. It is claimed to dissolve in concentrated sodium sulfide solution.^[1]

See also

• Gold(I) sulfide