Stability of Gold(I) Complexes with Triphenyl Derivatives of Group V Elements and with Dimethylchalconides

Abstract

Formation constants of AuClL and AuBrL complexes have been obtained by potentiometric titrations of Au(MeCN)₂ in acetonitrile at -20 °C (L = PPh₃, AsPh₃, SbPh₃, PPh₂Me, PPhMe₂, Me₂S, Me₂Se, Me₂Te, MeNC, ArNC). Au⁺ behaves as a typical class B metal. A general linear relation between log K’s of corresponding AuXL complexes suggesting that AuBr discriminates better than AuCl between soft ligands, breaks down when considering each family of ligands. Au(diolefin)₂⁺ complexes are not sufficiently more stable than Au(MeCN)₂⁺ to be isolated, however they may be obtained in the solid state by treating a solution of Et₄NAuCl₂ in acetone by AgClO₄ in the presence of excess diolefin.