Palladium(II) complexes bearing a salicylaldiminato ligand with a hydroxyl group: Synthesis, structures, deprotonation, and catalysis

Palladium complexes with a salicylaldiminato ligand bearing a hydroxyl group (1a and 1b) have been synthesized and characterized. The structures of these complexes were confirmed by X-ray crystallography. A reversible deprotonation/protonation of the hydroxyl moiety on 1b was observed, while such behaviour was impossible with a related palladium complex (1c) bearing a methoxyl group in place of the hydroxyl group. The deprotonation affected its catalytic behaviour: the activity for polymerization of methyl acrylate catalyzed by 1b considerably decreased in the presence of 1 equiv. of tBuOK.