trihalides, GaBr3 included, has been extensively studied thermodynamically, and the basicity of GaBr3 has been established with a number of donors. GaBr3 is capable of accepting an additional Br− ion or unevenly splitting its dimer to form [GaBr4]−, a tetrahedral ion of which crystalline salts can be obtained. This ionic complex is further capable of binding to . The Br− ion can be just as easily substituted with a neutral ligand. Typically these neutral ligands, with form GaBr3 L and sometimes GaBr3L2, will form a tetrahedral bipyramidal geometric structure with the Br in an equatorial position due to their large effective nuclear charge. Additionally, GaBr3 can be used as a catalyst in certain oxidative addition reactions. Uses GaBr3 is used as a catalyst in organic synthesis, with similar mechanism to GaCl3. However, due to its greater reactivity, it is sometimes disfavored because of the greater versatility of GaCl3. GaBr3 as well as other gallium trihalides and group 13 metal trihalides can be used as catalysts in the oxidative addition of organic compounds. It has been verified that the GaBr3 dimer cleaves unevenly into [GaBr4]− and [GaBr2]+. The entire mechanism is uncertain partly because intermediate states are not always stable enough for study, and partially because GaBr3 is studied less frequently than GaCl3. Ga(III) itself is a useful Lewis acid for organic reactions because its full d-electron shell makes it able to accept variable numbers of ligands, but will readily give up ligands if conditions prove favorable. See also GaCl3 Catalysis References Bromides Gallium compounds Metal halides