Gallium halides


There are three sets of gallium halides, the trihalides where gallium has oxidation state +3, the intermediate halides containing gallium in oxidation states +1, +2 and +3 and some unstable monohalides, where gallium has oxidation state +1.

Trihalides

All four trihalides are known. They all contain gallium in the +3 oxidation state. Their proper names are gallium fluoride, gallium chloride, gallium bromide and gallium iodide.
;GaF3
;GaCl3, GaBr3 and GaI3

Intermediate halides

Intermediate chlorides, bromides and iodides exist. They contain gallium in oxidation states +1, +2 and +3.
;Ga3Cl7
;GaCl2, GaBr2 and GaI2
;Ga2Br3 and Ga2I3

Monohalides

None of the monohalides are stable at room temperature. The previously reported GaBr and GaI produced from fusing gallium with the trihalide have been shown to be mixtures of metallic gallium with, respectively, Ga2Br3 and Ga2I3.
;GaCl and GaBr
;GaI

Anionic halide complexes

Salts containing GaCl4−, GaBr4− and GaI4− are all known. Gallium is very different from indium in that it is only known to form 6 coordinate complexes with the fluoride ion. This can be rationalised by the smaller size of gallium 62 pm, In.
Salts containing the Ga2Cl62− anion, where gallium has an oxidation state of +2, are known.

General references