Gold chalcogenides

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Gold chalcogenides are compounds formed between gold and one of the chalcogens, elements from group 16 of the periodic table: oxygen, sulfur, selenium, or tellurium.

  • Gold(III) oxide, Au2O3. Decomposes into gold and oxygen above 160 °C, and dissolves in concentrated alkalis to form solutions which probably contain the [Au(OH)4]− ion
  • Gold(I) sulfide, Au2S. Formed by passing hydrogen sulfide through solutions of gold(I) compounds.
  • Gold(III) sulfide, Au2S3, unstable in the presence of water.
  • Gold tellurides: Au2Te3, Au3Te5, and AuTe2 (approximate formulæ) are known as non-stoichiometric compounds. they show metallic conductivity. Au3Te5 is a superconductor at very low temperatures.

Natural gold tellurides, like calaverite and krennerite (AuTe2), petzite ( Ag3AuTe2), and sylvanite (AgAuTe4), are minor ores of gold (and tellurium). See telluride minerals for more information on individual naturally occurring tellurides.

A gold-sulfur bond is strong, not only involving inorganic sulfur ligands (Sx2-) but also thiolates. Gold has a high electronegativity (2.4 on the Pauling scale.[1] It forms moderately strong bonds to sulfur (126-146 kJ/mol).[2] This bond is widely employed to attach biological linkers, functional groups and other molecules to Colloidal gold nanoparticles for research purposes, especially live-cell microscopic imaging that depend on gold's surface plasmon resonance.

References

  1. ↑ Verne Biddle, Gregory Parker (2000). Chemistry: Precision and Design. A Beka Academy, Inc. p. 472. 
  2. ↑ Nuzzo, Ralph; Fusco, Florence; Allara, David (2002). "Preparation and Properties of Solution Adsorbed Monolayers of Organic Disulfides on Gold Surfaces". J. Am. Chem. Soc. 109 (8): 2358–2368. doi:10.1021/ja00242a020. 


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