The difunctional ligand o-Ph2PNHC6H4P(S)Ph2 (PS) has been prepared by treatment of the lithium amide salt of 2-(diphenylthiophosphanyl)aniline {2-[Ph2P(S)]C6H4NH2} with Ph2PCl. The new ligand was oxidised to give the mixed chalcogen species Ph2P(E)NHC6H4P(S)Ph2, by treatment with H2O2 (where E = O) or aerial oxidation by recrystallisation from MeOH, and by reaction with Se8 (where E = Se) in warm toluene. The complexes [MCl(η3-C3H5)(PS)] (M = Pt or Pd), cis-[PtCl2(PS)(PMe2Ph)], [(AuCl)(PS)], cis-[MCl2(PS)2] (M = Pt or Pd), cis-[PtMe2(PS)2] and trans-[PtMeCl(PS)2] have been synthesised by reaction of either [Pt(μ-Cl)(μ-η2:η1-C3H5)]4, [Pd(μ-Cl)(η3-C3H5)]2, [{PtCl(μ-Cl)(PMe2Ph)}2], [AuCl(tht)] (tht = tetrahydrothiophene), [PdCl2(cod)] or [PtX2(cod)] (X = Me or Cl; cod = cycloocta-1,5-diene) with (PS). In all these complexes the ligand (PS) is monodentate P-bound. Chloride abstraction from [MCl(η3-C3H5)(PS)] (M = Pt or Pd), cis-[PtCl2(PS)(PMe2Ph)], cis-[PtCl2(PS)2] and trans-[PtMeCl(PS)2], using Ag[ClO4], gave the monocationic [M(η3-C3H5)(PS)][ClO4] (M = Pt or Pd), cis-[PtCl(PS)(PMe2Ph)][ClO4], trans-[PtMe(PS)2][ClO4] or dicationic [Pt(PS)2][ClO4]2 compounds in which the ligand (PS) is κ2-P,S-bound. All compounds described here have been characterised by a combination of 31P{1H} and 1H NMR spectroscopy, microanalyses, FAB mass spectrometry and IR spectroscopy. The molecular structures of [AuCl(Ph2PNHC6H4P(S)Ph2-P)] in which there is an intramolecular hydrogen-bonding interaction between the amine proton and the sulfur atom of the thiophosphoryl group and trans-[Pt(Ph2PNHC6H4P(S)Ph2-κ2-P,S)2][ClO4]2·CH2Cl2·2H2O in which the perchlorate counterions are associated by hydrogen-bonding interactions to the amine protons of the κ2-P,S ligands have been determined by single-crystal X-ray diffraction. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)