Caesium auride

Names
	IUPAC name Caesium auride
Identifiers
CAS Number	12256-37-0 ;
3D model (JSmol)	covalent form: Interactive image; ionic form: Interactive image;
PubChem CID	71308168;
	InChI InChI=1S/Au.Cs Key: COOMJVRPVOQALF-UHFFFAOYSA-N ;
	SMILES covalent form: [Cs][Au]; ionic form: [Cs+].[Au-];
Properties
Chemical formula	AuCs
Molar mass	329.872022 g·mol−1
Appearance	Yellow crystals
Melting point	580 °C (1,076 °F; 853 K)
Solubility in water	reacts violently
Structure
Crystal structure	CsCl
Lattice constant	a = 4.24 Å
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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	Infobox references

Caesium auride is the inorganic compound with the formula CsAu. It is the Cs⁺ salt of the unusual Au⁻ anion.^[2]

Preparation and reactions[]

CsAu is obtained by heating a stoichiometric mixture of caesium and gold. The two metallic-yellow liquids react to give a transparent product. A solution of CsAu in liquid ammonia is brown, and the solid is yellow (the colour of both metals making up the compound). The ammonium adduct is dark blue. Despite being a compound of two metals, CsAu lacks metallic properties since it is a salt with localized charges.

The compound hydrolyzes readily, yielding caesium hydroxide, metallic gold, and hydrogen.

2 CsAu + 2 H₂O → 2 CsOH + 2 Au + H₂

Solutions in ammonia undergo metathesis with tetramethylammonium loaded ion exchange resin to give tetramethylammonium auride.^[3]

References[]

^ ^a ^b Kienast, Gerhard; Verma, Jitendra; Klemm, Wilhelm (June 1961). "Das Verhalten der Alkalimetalle zu Kupfer, Silber und Gold". Zeitschrift für anorganische und allgemeine Chemie (in German). 310 (3): 143–169. doi:10.1002/zaac.19613100304.
^ Peer, William J.; Lagowski, J. J. (1978). "Metal-Ammonia Solutions. 11. Au⁻, a Solvated Transition Metal Anion". J. Am. Chem. Soc. 100: 6260–6261. doi:10.1021/ja00487a064.
^ Jansen, Martin (2005-11-30). "Effects of relativistic motion of electrons on the chemistry of gold and platinum". Solid State Sciences. 7 (12): 1464–1474. Bibcode:2005SSSci...7.1464J. doi:10.1016/j.solidstatesciences.2005.06.015.

Caesium auride

Preparation and reactions[]

References[]

Further reading[]