Gold halide
Gold halides are compounds of gold 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°.[1]
The monomeric AuF molecule has been detected in the gas phase.[2]
Trihalides
The triiodide does not exist.[citation needed] AuCl3 readily forms out of the elements at temperatures below 254 °C. It is a volatile red solid. The volatile species is the dimer Au2Cl6.[citation needed]. Likewise, AuBr3 can be formed from the elements and exists primarily as the dimer Au2Br6.
Gold(III) fluoride, AuF3, has a unique polymeric helical structure, containing corner-sharing {AuF4} squares.
Pentahalides
Gold(V) fluoride, AuF5, is the only known example of gold in the +5 oxidation state. It most commonly occurs as the dimer Au2F10.
