Gold halides are compounds of
gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...
with the
halogens.
Monohalides
AuCl,
AuBr, and
AuI are all crystalline solids with a structure containing alternating linear chains: ..-X-Au-X-Au-X-Au-X-... The X-Au-X angle is less than 180°.
The monomeric AuF molecule has been detected in the gas phase.
Trihalides
Gold triiodide does not exist or is unstable.
Gold(III) fluoride
Gold(III) fluoride, , is an orange solid that sublimes at 300 °C. It is a powerful fluorinating agent.
Preparation
AuF3 can be prepared by reacting AuCl3 with F2 or BrF3.
Structure
The crystal structure of AuF3 consists of spirals ...
, AuF
3, has a unique polymeric helical structure, containing corner-sharing {AuF
4} squares.
Pentahalides
Gold(V) fluoride
Gold(V) fluoride is the inorganic compound with the formula Au2F10. This fluoride compound features gold in its highest known oxidation state. This red solid dissolves in hydrogen fluoride but these solutions decompose, liberating fluorine.
Th ...
, AuF
5, is the only known example of gold in the +5
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
. It most commonly occurs as the dimer Au
2F
10.
References
Metal halides
Gold–halogen compounds