Gold (III) oxide

Crystal structure
	__ Au 3+ __ O 2−
General
Surname	Gold (III) oxide
Ratio formula	Au 2 O 3
Brief description	brown powder
External identifiers / databases
EC number	215-122-1
ECHA InfoCard	100,013,748
PubChem	164805
ChemSpider	144478
Wikidata	Q415247
properties
Molar mass	441.93 g · mol -1
Physical state	firmly
density	3.6 g cm −3
Melting point	Decomposes at approx. 150 ° C into Au and O 2
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315-319
	P: 305 + 351 + 338
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Gold (III) oxide (Au ₂ O ₃ ) is the most stable known oxide of the chemical element gold . It is a red-brown, crystalline, light-sensitive solid. The compound is thermally unstable and decomposes back into the elements above about 160 ° C. Au ₂ O ₃ has a distorted square-planar crystal structure consisting of AuO ₄ units.

presentation

Due to the noble character of elemental gold, the connection cannot be established by oxidizing it with oxygen . However, it can be represented by the direct reaction of gold with an oxygen plasma . Chemically, one starts from trichlorogold hydrate AuCl ₃ · H ₂ O (actually hydrogen trichlorohydroxidoaurate (III) H [AuCl ₃ (OH)]) or tetrachloridogauric acid H [AuCl ₄ ] · 4 H ₂ O, which is stable in aqueous solution Sodium carbonate is added when a brown precipitate Au ₂ O ₃ · x H ₂ O separates out. After drying over silica gel, this water splits off and results in Au ₂ O ₃ · 2-3 H ₂ O. This can then be purified further by tempering for four weeks in water at 280 ° C and 3000 bar pressure (see principle of the smallest compulsion ) polycrystalline and anhydrous gold (III) oxide Au ₂ O ₃ .

use

Gold oxide can be used to color glasses ( gold ruby glass ), special applications in optoelectronics are also possible.

Individual evidence

^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 .
↑ ^a ^b ^c data sheet gold (III) oxide from AlfaAesar, accessed on February 2, 2010 ( PDF )(JavaScript required) . .
↑ ^a ^b Data sheet Gold (III) oxide hydrate from Sigma-Aldrich , accessed on April 3, 2011 ( PDF ).
↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1090.

Web links

Jörg Michael Gottfried: CO oxidation on gold, adsorption and reaction of oxygen, carbon monoxide and carbon dioxide on an Au (110) - (1x2) surface , dissertation at the FU Berlin
3D images with the help of gold oxide

[1] AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 .

[alfa-2] ta sheet gold (III) oxide from AlfaAesar, accessed on February 2, 2010 ( PDF )(JavaScript required) . .

[Sigma-3] Data sheet Gold (III) oxide hydrate from Sigma-Aldrich , accessed on April 3, 2011 ( PDF ).

[Brauer-2-4] Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1090.