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

• Published in: Bulletin of the Korean Chemical Society 2015, 36(2), , pp.609-617
• Main Authors: Kim, Sunghoon, Song, Yujin, Lee, Ha-Jin, Jeon, Jongho, Park, Sang Hyun, Lee, Hyosun
• Format: Article
• Language: English
• Subjects: Induced chirality; MMA polymerization; N-Methyl-N-(pyridin-2-ylmethyl)aniline; Palladium(II) complex; Syndiotacticity; 화학
• ISSN: 1229-5949; 0253-2964; 1229-5949
• DOI: 10.1002/bkcs.10119

The N‐methyl‐N‐(pyridin‐2‐ylmethyl)aniline and its derivatives containing square‐planar palladium(II) complexes, [L n PdCl2] (L n  = L1–L5), were structurally characterized. The catalytic activity of Pd(II) complexes toward the methyl methacrylate (MMA) polymerization in the presence of modified methylaluminoxane (MMAO) was compared to that of the corresponding reference Pd(II) complex, [PdCl2], at 60 °C. 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.