Selective Formation of Mononuclear Palladium and Acetonitrile-Bridged Dinuclear Palladium Complexes Containing a Chiral Tridentate Ligand.

From the chiral Schiff base tridentate ligand , unusual acetonitrile-bridged dinuclear palladium complex and organopalladium complex were synthesized selectively by using acetonitrile and ethanol, respectively. The chiral tridentate Schiff base ligand was bound to the palladium metal center with different chelation modes ([ONO] for and [CNO] for ). Complex constitutes the first example of dinuclear metal complexes connected only by a bridging acetonitrile, in which an exceptionally short C≡N bond distance [0.945(12) Å] of bridged acetonitrile was observed. To study the influence of a phenyl group attached to an imine, the phenyl-free ligand was prepared and used. In that case, an acetonitrile bridge was not observed. Theoretical calculation studies supporting the formation of and are favored.