An X-Ray Investigation of the Structures of the Tetrachloro- and Tetrabromoaurate(III) Ions in Aqueous Solution

Abstract The structures of the AuCl4− and the AuBr4− complexes in aqueous solutions have been determined from X-ray scattering measurements on concentrated solutions of tetrachloroauric and tetrabromoauric acids. Both the tetrachloroaurate(III) and the tetrabromoaurate(III) complexes were found to have a square planar symmetry. The values obtained for the interatomic distances within the complexes are: Au–Cl, 2.291 Å; cis-Cl–Cl, 3.24 Å; trans-Cl–Cl, 4.58 Å; Au–Br, 2.432 Å; cis-Br–Br, 3.44 Å; trans-Br–Br, 4.86 Å.