Synthesis and Characterization of Allyl(β-ketoimmato)palladium(II) Complexes: New Precursors for Chemical Vapor Deposition of Palladium Thin Films

Treatment of β-ketoiminates with [(allyl)Pd(μ-Cl)]₂ affords volatile, air-stable allyl(β-ketoiminato)palladium(II) complexes. The structure of [(methallyl)Pd(Phacac)] (Phacac = MeCOCHCMeNPh) was determined by single-crystal X-ray diffraction. In solution ¹H NMR analyses indicate either a direct rotation of a planar allyl ligand about the allyl−palladium axis or a solvent-assisted exchange process involving the transient formation of a monodentate ketoiminato ligand. The physical properties of the complexes were modified by altering the β-ketoiminato or the η³-allyl ligands. Some derivatives are liquid at room temperature and were known to be suitable for chemical vapor deposition of Pd thin films.