Gold (III) bromide is frequently used as the auric bromide and it is defined as the inorganic salt that is mainly used as the catalyst in organic or inorganic synthesis. The chemical formula for the compound is AuBr3 and its molecular weight is 436.69 g mol-1 approx. It is formed when one gold cation combines with 3 bromide anions and bounded by ionic bonds.
It is mostly available as the dimer and its chemical structure could be given as below.
The compound is not found in nature but it can be prepared chemically from gold and bromide which is a synthetic method that was invented in the 19th century. The basic component for preparing this compound includes gold and bromide. It should be heated at 150-degree Celsius approx. to form the final product.
2 Au + 3 Br2 → Au2Br6
Au2Cl6 + 6 HBr → 6 HCl + Au2Br6
When looking at the physical properties of the compound, it is a blue to grey or black crystalline solid powder whose density is 5.92 g mL-1 and melting point can be defined as the 97.5 ºC. at high temperature, it will start decomposing. Also, it will decompose when reacts with glycerol. It is not soluble with water or ethanol but it reacts quickly with hydrobromic acid or Lewis bases.
This is a popular catalyst that is frequently used with chemical industries and organic synthesis processes due to its Lewis acid properties. It can be used as the medicine as well. Further, it is used by criminalists to test fluids or alkaloids.