Displacement of chelate ligands from planar four-co-ordinate complexes. Part I. Reactions of some gold(III) complexes of 2,2′-bipyridyl

Abstract

The kinetics of nucleophilic displacement of the chelate 2,2′-bipyridyl ligand (bipy) from the complex [Au(bipy)X₂]⁺ by X^–(X = Cl or Br) have been measured in aqueous methanol solution at 25 °C. The rate constant shows dependences on hydrogen-ion concentration and on the first and third power of chloride-ion concentration. Details of the mechanism are discussed and compared with others involving replacement of chelate ligands from planar complexes of d⁸ transition-metal ions.