Palladium(II) complexes containing N,N′-bidentate imine ligands derived from picolinaldehyde and substituted anilines: Synthesis, structure and polymerisation of methyl methacrylate

Palladium(II) complexes, LnPdCl2 (L-n=L-A-L-I), with N,N'-bidentate imine ligands derived from picolinaldehyde and substituted anilines have been synthesized and structurally characterized. Molecular structures revealed a distorted square plane geometry around Pd(II) centre in LnPdCl2 (L-n=L-A-L-C) obtained via coordination with pyridine and imine nitrogens and two chloro ligands. Pd(II) complexes LnPdCl2 (L-n=L-A-L-I) initiate polymerisation of methylmethacrylate (MMA) in the presence of modified methylaluminoxane (MMAO). The complex LIPdCl2 (of which the ligand was N-furfuryl substituted) showed the highest catalytic activity for the polymerisation of MMA with an activity of 7.08x10(4) g PMMA/mol.Pd.h at 60 degrees C. All the complexes yielded syndio-rich poly(methyl methacrylate) (PMMA) ([rr]?=?0.70). Notably, the substituents on the imine moiety of the iminopyridine fragments affects the activities towards MMA polymerization, whereas the stereoselectivities remained unchanged. (C) 2018 Elsevier Ltd. All rights reserved.