A convenient route to prepare mono- and dinuclear 2-benzoylpyridine palladacycles with imidate ligands

Abstract New dinuclear cyclometallated palladium complexes of general formula [{Pd(μ-NCO)(CˆN)} 2 ] (CˆN = 2-benzoylpyridine (bzpy) I ; NCO  = saccharinate (sacc) a , Phthalimidate (phthal) b or 4,5-dichlorophthalimidate (DiClphthal) c have been synthesized by a simple acid-base reaction involving the di-μ-hydroxo-precursor [{Pd(μ-OH)(bzpy)} 2 ] recently reported. Analogous to Ic , complex IIc with CˆN = 2-phenylpyridine (phpy) II has also been prepared, meaning the first examples reported to date of complexes including 4,5-dichlorophthalimidate as ligand coordinating a metal centre. The reaction of bridged imidato precursors against triphenylphosphine to form the mononuclear N-bonded imidato derivatives of general formula [Pd(CˆN)(N-imidate)(PPh 3 )] IaP , IbP , IcP and IIcP has been achieved under mild conditions. The new complexes were characterized by partial elemental analyses and spectroscopic methods. Structural characterization by X-ray diffraction of Ib and IIcP , the first crystal structure of a complex containing 4,5-diClphthal that has been deposited to date on the Cambridge Structural Database, have confirmed the proposed formulae.