Gold(III) chloride

Gold(III) chloride
Names



IUPAC name Gold(III) trichloride
Other names Auric chloride Gold trichloride
Identifiers
CAS Number	13453-07-1^Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:30076^Y
ChemSpider	24244^N
ECHA InfoCard	100.033.280
PubChem	26030
RTECS number	MD5420000
UNII	15443PR153^Y
InChI InChI=1S/Au.3ClH/h;31H/q+3;;;/p-3^Y Key: RJHLTVSLYWWTEF-UHFFFAOYSA-K^Y InChI=1/Au.3ClH/h;31H/q+3;;;/p-3 Key: RJHLTVSLYWWTEF-DFZHHIFOAC
SMILES [Cl-]1.[Cl-]2.[Cl-]([Au+3]1)2
Properties
Chemical formula	AuCl₃ (exists as Au₂Cl₆)
Molar mass	303.325 g/mol
Appearance	Red crystals (anhydrous); golden, yellow crystals (monohydrate)
Density	4.7 g/cm³
Melting point	254 °C (489 °F; 527 K) (decomposes)
Solubility in water	68 g/100 ml (cold)
Solubility	soluble in ether, slightly soluble in liquid ammonia
Magnetic susceptibility (χ)	−112·10⁻⁶ cm³/mol
Structure
Crystal structure	monoclinic
Coordination geometry	Square planar
Hazards
Main hazards	Irritant
Safety data sheet	See: data page
R-phrases	R36/37/38
S-phrases	S26 S36
Related compounds
Other anions	Gold(III) fluoride Gold(III) bromide
Other cations	Gold(I) chloride Silver(I) chloride Platinum(II) chloride Mercury(II) chloride
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (ε_r), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N (what is ^YN ?)
Infobox references

Gold(III) chloride, traditionally called auric chloride, is a chemical compound of gold and chlorine. With the molecular formula Au₂Cl₆, the name gold trichloride is a simplification, referring to the empirical formula, AuCl₃. The Roman numerals in the name indicate that the gold has an oxidation state of +3, which is common for gold compounds. There is also another related chloride of gold, gold(I) chloride (AuCl). Chloroauric acid, HAuCl₄, the product formed when gold dissolves in aqua regia, is sometimes referred to as "gold chloride" or "acid gold trichloride". Gold(III) chloride is very hygroscopic and highly soluble in water as well as ethanol. It decomposes above 160 °C or in light.

AuCl₃ exists as a chloride-bridged both as a solid and as a vapour, at least at low temperatures.Gold(III) bromide behaves analogously. The structure is similar to that of iodine(III) chloride.

In gold(III) chloride, each gold center is square planar, which is typical of a metal complex with a d⁸ electron count. The bonding in AuCl₃ is considered somewhat covalent.

Gold(III) chloride is most often prepared by passing chlorine gas over gold powder at 180 °C:

Another method of preparation is by reacting Au³⁺ species with chloride to produce tetrachloroaurate. Its acid, chloroauric acid, is then heated to eliminate hydrogen chloride gas. Reaction with aqua regia produces gold(III) chloride:

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