Palladium and platinum organochalcogenolates and their transformation into metal chalcogenides

Platinum group metal chalcogenides find extensive applications in catalysis and in the electronic industry. To develop an efficient low temperature clean preparation of these materials, molecular routes have been explored. Thus the chemistry of mononuclear organochalcogenolates of the type [M(ER¢)2(PR3)2], binuclear benzylselenolates, [M2Cl2(m-SeBz)2(PR3)2], allylpalladium complexes [Pd2(m-ER)2(h3-C4H7)2] and palladium/platinum sulphido/selenido-bridged complexes, [M2(m-E)2L4] (M = Pd or Pt; E = S, Se or Te; L = tertiary phosphine ligand) has been investigated. All the complexes have been characterized by elemental analysis, NMR (1H, 31P, 77Se, 195Pt) spectroscopy and in some cases by X-ray diffraction. The thermal behaviour of these complexes has been studied by TGA. The pyrolysis of allylpalladium complexes in refluxing xylene yields Pd4E as established by analysis and XRD patterns.