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Ge Y, Cai Q, Wang Y, Gao J, Chi Y, Dai S. Synthesis of High-Molecular-Weight Branched Polyethylene Using a Hybrid “Sandwich” Pyridine-Imine Ni(II) Catalyst. Front Chem 2022; 10:886888. [PMID: 35601545 PMCID: PMC9114440 DOI: 10.3389/fchem.2022.886888] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Most pyridine-imine Ni(II) and Pd(II) catalysts tend to yield low-molecular-weight polyethylene and ethylene-based copolymers in olefin insertion polymerization, as the unilateral axial steric structure of such complexes often cannot provide effective shielding of the metal center. In this study, we synthesized a series of hybrid “semi-sandwich” and “sandwich” type pyridine-imine Ni(II) complexes by incorporating diarylmethyl or dibenzosuberyl groups onto 8-aryl-naphthyl motif. The as-prepared Ni(II) complexes afforded highly branched polyethylene with high molecular weights (level of 105 g/mol), and moderate activities (level of 105 g/(molh)) in ethylene polymerization. Most interestingly, compared to “semi-sandwich” Ni(II) complexes bearing (2-diarylmethyl-8-aryl)naphthyl units, the “full-sandwich” counterpart containing (2-dibenzosuberyl-8-aryl)naphthyl motif was able to produce higher-molecular-weight polyethylene with higher branching density. In addition, the effect of remote non-conjugated electronic substituents in diarylmethyl groups of the Ni(II) system was also observed in ethylene polymerization.
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Affiliation(s)
- You Ge
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, China
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, China
| | - Qi Cai
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, China
| | - Yuyin Wang
- Key Laboratory of Advanced Structural Materials of Ministry of Education, College of Material Science and Engineering, College of Chemistry and Life Science, Advanced Institute of Materials Science, Changchun University of Technology, Changchun, China
| | - Jiangang Gao
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, China
- *Correspondence: Jiangang Gao, ; Yue Chi, ; Shengyu Dai,
| | - Yue Chi
- Key Laboratory of Advanced Structural Materials of Ministry of Education, College of Material Science and Engineering, College of Chemistry and Life Science, Advanced Institute of Materials Science, Changchun University of Technology, Changchun, China
- *Correspondence: Jiangang Gao, ; Yue Chi, ; Shengyu Dai,
| | - Shengyu Dai
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, China
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, China
- *Correspondence: Jiangang Gao, ; Yue Chi, ; Shengyu Dai,
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