Palladium(II) complexes of 2-acylpyridines. The crystal structure of dibromo bis(phenyl-2-pyridyl ketone)palladium(II)

Abstract

Reaction of Pd(II) with 2-pyridine-carboxaldehyde (PC), methyl 2-pyridyl ketone (MPK) and phenyl 2-pyridyl ketone (PPK) in methanolic solutions gave six new complexes which have been characterized by elemental analysis, conductivity measurements, and IR and UV-Vis spectroscopic techniques. The ligands PC and PPK behave as monodentate and exhibit nitrogen coordination while MPK exhibits N, O ligation through the ring nitrogen and carbonylic oxygen atom in the production of a five membered chelate ring. The crystal structure of the Pd(II) complex of PPK has been determined by single crystal X-ray diffraction methods. Crystal data are: monoclinic space group P21/n, a=8.707(3), b=14.394(3), c=8.967(3) Å, β=93.45(2)°, Dcalc=1.871 g cm−3, V=1121.8 Å3, RF=0.062; Rw=0.068, GOF=2.0. The complex molecule is the trans-isomer of a square planar structure and the central Pd(II) lies on a center of symmetry and is coordinated by two bromides and two pyridine ring nitrogen atoms.