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

Abstract

Treatment of MCl 2(P ∩P) or MCl 2(P n Pr 3) 2 with two equivalents of ArCOSeK readily yields cis-[M(SeCOAr) 2(P ∩P)] and trans-[M(SeCOAr) 2(P n Pr 3) 2], respectively (M = Pd or Pt; Ar = Ph or 4-MeC 6H 4; P ∩P = dppm, dppe, dppp). The reaction of Pd(SeCOAr) 2(dppe) with PdCl 2(dppe) in the presence of NaBPh 4 in methanol gave a tri-nuclear ionic complex, [Pd 3(μ 3-Se) 2(dppe) 3][BPh 4] 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(P n Pr 3) 2] either in tri- n-butylphosphate (TBP) (at 200 °C) or in the solid state (furnace heating at 350 °C) gave Pd 17Se 15.