Hard ligands as donors to soft metals. Part 1. Formation of oxygen-bonded dimethyl sulphoxide complexes of palladium(II) and platinum(II) promoted by steric crowding

Abstract

Cationic oxygen-bonded dimethyl sulphoxide (dmso) complexes of the types [M(Ph₂PCH₂CH₂PPh₂)(dmso)₂][X]₂ and [M(Ph₂PCH₂CH₂PPh₂)(dmso)Cl][X], where X is a non-co-ordinating anion, have been prepared with palladium(II) and platinum(II). The bis(sulphoxide) complexes are stable in solution and in the solid state, however the sulphoxide ligand in the mono(sulphoxide) complexes is very labile. In solution [Pd(Ph₂PCH₂CH₂PPh₂)-(dmso)Cl][X] readily forms the corresponding thioether (SMe₂) complex by loss of oxygen from the dimethyl sulphoxide.