The Crystal and Molecular Structure of [Pd(tfac)(tfac-O){P(o-tolyl)3}] Containing an O-Unidentate 1,1,1-Trifluoro-2,4-pentanedionate Anion as a Ligand

The title complex crystallizes in the monoclinic space group C2/c with a=24.900(6) Å, b=8.272(2) Å, c=30.437(9) Å, and β=97.23(2)°. The structure analysis, which converged at R=0.061 and Rw=0.083 with 3017 reflections for which Fo2>3σ(Fo2), showed that the palladium has a complete square-planar coordination geometry. While one of the tfac ligands is chelating, the other is bound to the metal only through the carbonyl oxygen adjacent to CH3. The O-unidentate tfac ligand lies trans to the CF3CO moiety of chelating tfac and has a planar structure in which the dangling CF3CO group is situated trans to the bonding oxygen atom with respect to the C=C bond. The ab initio MO calculation for the Z,Z-form of the tfac anion indicated that the coordination ability of the acetyl oxygen is higher than that of the trifluoroacetyl oxygen in consistence with the observed structure.