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 180°.

Trihalides
The triiodide does not exist. AuCl3 readily forms out of the elements at temperatures below 254oC. It is a volatile red solid. The volatile species is the dimer Au2Cl6.