Influence of phenyl ring substituents in the cyclometallation of Schiff base ligands: crystal and molecular structures of [Pd-{3,4-(OCH2O)C6H2C(H)N(Cy)-C2,N}(μ-O2CMe)]2 and [Pd-{3,4-(OCH2CH2O)C6H2C(H)N(Cy)-C6,N}(μ-O2CMe)]2

Reaction of Pd(OAc)2 with the Schiff base ligands 3,4-{O(CH2)nO}C6H3C(H)NR (n=1, 2; R=Cy, 3,4-(OCH2O)C6H3CH2-) leads to dinuclear cyclometallated products in which each palladium atom is C,N bonded to a deprotonated organic ligand, and to two acetate groups which bridge both metal centers. Treatment of 3,4-{O(CH2)2O}C6H3C(H)NCH2CH2NMe2 with [PtMe2(COD)] gives mononuclear compounds with the ligand as terdentate through the [C, N, N] atoms. The regioselectivity of the cyclometallation processes is discussed by 1H-NMR spectroscopy and X-ray diffraction studies.