Palladium(II) Complexes with N,N′‐Bidentate N‐Methyl‐N‐(pyridin‐2‐ylmethyl)aniline and its Derivatives: Synthesis, Characterization, and Methyl Methacrylate Polymerization

Abstract

The N,N′‐bidentate [( N , N ′) PdCl2 ] complexes [i.e., [ L n PdCl2 ] (L n = L1–L5 )] were synthesized by the reaction of [Pd( CH3CN ) 2Cl2 ] with N‐methyl‐N‐(pyridin‐2‐ylmethyl)aniline ( L1 ) and its derivatives ( L2–L5 ) in ethanol. The molecular structures of [ L n PdCl2 ] (L n = L1–L3 ) were characterized using X‐ray crystallography, which showed that the Pd atom in the Pd(II) complexes had a square planar geometry involving two nitrogen atoms of N,N′‐bidentate and two chlorido ligands. The complexes [ L n PdCl2 ] (L n = L1–L5 ) were investigated for methyl methacrylate (MMA) polymerization in the presence of modified methylaluminoxane (MMAO) at 60 °C. Specifically, complex [ L1PdCl2 ] showed moderate catalytic activity toward MMA polymerization with an activity of 3.03 × 104 g poly(methylmethacrylate) (PMMA)/mol Pd·h and PMMA syndiotacticity (characterized by 1H NMR spectroscopy) of ~0.68.