C,O-Chelates of the Trifluoroacetylacetonate Dianion with Palladium(II). Molecular Structure of [Pd(tfac(2–)-C,O)(PPh3)(2,6-Me2-py)]

Reactions of bis(trifluoroacetylacetonato)palladium(II), [Pd(tfac)2], with tertiary phosphines followed by pyridine or its derivatives afforded a series of the [Pd(tfac(2–)-C,O)LL′]-type complexes which contain a C,O-chelating trifluoroacetylacetonate dianion and a couple of tertiary phosphine and/or heterocyclic nitrogen base ligands (L and L′). Their structures in solution were studied by 1H, 13C, 19F, and 31P NMR spectroscopy and the molecular structure in a crystal of [Pd(tfac(2–)-C,O)(PPh3)(2,6-Me2-py)]·C6H6 containing triphenylphosphine and 2,6-dimethylpyridine as L and L′ was determined by means of X-ray diffraction.