Gold halides are compounds of gold with the halogens. Gold halides are compounds of gold with the halogens. 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. Gold triiodide does not exist or is unstable. Gold(III) fluoride, AuF3, has a unique polymeric helical structure, containing corner-sharing {AuF4} squares. Gold(V) fluoride, AuF5, is the only known example of gold in the +5 oxidation state. It most commonly occurs as the dimer Au2F10.