Palladium(II) and platinum(II) monoselenocarboxylates: Synthesis, spectroscopy, structure and their use as molecular precursors for metal selenides

Treatment of MCl2(P∩P) or MCl2(PnPr3)2 with two equivalents of ArCOSeK readily yields cis-[M(SeCOAr)2(P∩P)] and trans-[M(SeCOAr)2(PnPr3)2], respectively (M = Pd or Pt; Ar = Ph or 4-MeC6H4; P∩P = dppm, dppe, dppp). The reaction of Pd(SeCOAr)2(dppe) with PdCl2(dppe) in the presence of NaBPh4 in methanol gave a tri-nuclear ionic complex, [Pd3(μ3-Se)2(dppe)3][BPh4]2. These complexes were characterized by UV–Vis, IR and NMR spectroscopy. The complex [Pt(SeCOPh)2(dppp)] has been structurally characterized by X-ray crystallography. The coordination environment around square planar platinum atom is defined by chelating dppp ligand and two unidentate selenocarboxylates bonded through selenium atoms. Pyrolysis of [Pd(SeCOAr)2(PnPr3)2] either in tri-n-butylphosphate (TBP) (at 200 °C) or in the solid state (furnace heating at 350 °C) gave Pd17Se15.