This compound exists as the dimer Al2Br6 in the condensed phase. It is a strong Lewis acid, more so than AlCl3, and this together with its dimer molecular structure in both solid and liquid phases, make it more reactive than AlCl3, forming adducts and complexes with most Lewis bases [3]. The increased reactivity makes it a suitable choice when AlCl3-catalyzed reactions are slow or hard to start.