| Abstract | Palladium(II) and platinum(II) complexes of two chelating ditelluroether ligands [M(L-L)X2] (M = Pd or Pt, X = Cl, Br, or I, and L-L = PhTe(CH2)3TePh or MeTe(CH2)3TeMe) are described. The complexes have been characterized by analysis and IR, UV-visible and multinuclear NMR (1H, 125Te{1H}, 195Pt{1H}) spectroscopy. The NMR studies show that two diastereoisomers of the ligand are present in solution in each complex, meso and dl invertomers, with the former having the higher abundance. The structure of [Pd{meso-PhTe(CH2)3TePh}Br2] has been determined by X-ray diffraction. Crystals belong to the triclinic crystal system, space group P1, with a = 8.968 (1) Å, b = 10.978 (1) Å, c = 11.070 (2) Å, α = 108.16 (1)°, β = 113.15 (1)°, γ = 98.95 (1)°, and Z = 2. The structure was refined to an R value of 0.023 from 2545 reflections (F > 3σf(F)). The trends in the 125Te and 195Pt NMR chemical shifts and 1J(195Pt-125Te) coupling constants are reported and discussed and are compared with data on the corresponding diselenoether complexes. Close parallels exist between 125Te and 77Se chemical shifts in comparable complexes. Attempts to halogen oxidize the complexes to the M(IV) state have failed. © 1989 American Chemical Society. |
