Chemistry:Gold(III) sulfide

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Gold(III) sulfide
Names
IUPAC name
Gold(III) sulfide
Other names
Auric sulfide, Gold trisulfide, Digold trisulfide
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 215-124-2
UNII
Properties
Au
2
S
3
Molar mass 490.11 g·mol−1
Appearance Black powder
Density 8.750 g/cm3
Insoluble
Hazards
GHS pictograms GHS07: Harmful
GHS Signal word Warning
H315, H319, H335
P261, P264, P271, P280, P302+352, P304+312, P304+340, P305+351+338, P312, P321, P332+313, P337+313, P362, P403+233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Gold(III) sulfide or auric sulfide is an inorganic compound with the formula Au
2
S
3
. 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.

Claims

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

2 Li[AuCl
4
] + 3 H
2
S → Au
2
S
3
+ 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 H
2
O → 8 Au + 3 H
2
SO
4
+ 18 H+

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

Au
2
(SO
4
)
3
+ S
8
→ Au
2
S
3
+ Au
2
S + 4 SO
3
+ 6 SO
2

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

References

  1. 1.0 1.1 1.2 1.3 Senftle, F. E.; Wright, D. B. (December 12, 1985). "Synthesis of Au2S and Au2S3 using H2S, short-chain and ring-structured sulfur as sulfur sources". Zeitung für Naturforschung 41 (41b): 1081–1084. doi:10.1515/znb-1986-0904. https://zfn.mpdl.mpg.de/data/Reihe_B/41/ZNB-1986-41b-1081.pdf. 
  2. Antony, U.; Lucchesi, A. (11 July 1890). "Del sulfuro aurico Au2S3" (in it). Gazzetta Chimica Italiana: 601–606. https://babel.hathitrust.org/cgi/pt?id=njp.32101045086079&view=1up&seq=617. 
  3. 3.0 3.1 Kristl, M.; Drofenik, M. (2003). "Preparation of Au2S3 and nanocrystalline gold by sonochemical method". Inorganic Chemistry Communications 6 (12): 1419–1422. doi:10.1016/j.inoche.2003.08.027. https://reader.elsevier.com/reader/sd/pii/S138770030300296X.