Versatile ligand behaviour of phenyl 2-pyridyl ketone benzoylhydrazone in palladium(II) complexes

A series of monometallic palladium(II) complexes with phenyl 2-pyridyl ketone benzoylhydrazone (H(2)L) has been synthesized and characterized. The spectroscopic and diffractometric data have revealed a versatile ligand behaviour which mainly depends on the the palladium salt reagent. From the reaction of palladium acetate a cyclopalladated complex, [PdL(MeCN)], was isolated, the exact nature of which has been established by X-ray diffraction. With palladium chloride two complexes, [Pd(HL)(2)] and [Pd(HL)Cl], were obtained with the monodeprotonated hydrazone behaving as an N,N-bidentate and N,N,O-terdentate ligand, respectively.