Platinum(II), palladium(II), and nickel(II) thiosalicylate complexes

Abstract

A series of platinum(II), palladium(II) and nickel(II) complexes containing thiosalicylate ligands have been prepared by the reaction of [MX ₂ L ₂ ] complexes [X = halide or acetate; L or L ₂ = ancillary neutral donor ligand such as a tertiary phosphine or cycloocta-1,5-diene (cod)] with thiosalicylic acid in methanol with added pyridine. Displacement of the cod ligand from [Pt(SC ₆ H ₄ CO ₂ )(cod)] with phosphines and phosphites allows the synthesis of additional derivatives. The complexes [Pt(SC ₆ H ₄ CO ₂ )(PPh ₃ ) ₂ ] and [Ni(SC ₆ H ₄ CO ₂ )(dppp)] [dppp = 1,3-bis(diphenylphosphino)propane] have been the subjects of single-crystal X-ray diffraction studies. While both complexes contain the expected approximately square-planar metal co-ordination environments, the plane of the thiosalicylate ligand is inclined at an angle of 45.9° to the platinum co-ordination plane, but at only 9.4° to the nickel plane. The results of an electrospray mass spectrometry study of the thiosalicylate complexes and some related thioglycolate, 2-sulfanylpropionate and salicylate derivatives are discussed in terms of the stabilities of the complexes.