Biphenyl-Bridged 6-(1-Aryliminoethyl)-2-iminopyridylcobalt Complexes: Synthesis, Characterization, and Ethylene Polymerization Behavior

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• 作者：Qifeng Xing ; Tong Zhao ; Shizhen Du ; Wenhong Yang ; Tongling Liang ; Carl Redshaw ; Wen-Hua Sun
• 刊名：Organometallics
• 出版年：2014
• 出版时间：March 24, 2014
• 年：2014
• 卷：33
• 期：6
• 页码：1382-1388
• 全文大小：294K
• 年卷期：v.33,no.6(March 24, 2014)
• ISSN：1520-6041

文摘

A series of biphenyl-bridged 6-(1-aryliminoethyl)-2-iminopyridine derivatives reacted with cobalt dichloride in dichloromethane/ethanol to afford the corresponding binuclear cobalt complexes. The cobalt complexes were characterized by FT-IR spectroscopy and elemental analysis, and the structure of a representative complex was confirmed by single-crystal X-ray diffraction. Upon activation with either MAO or MMAO, these cobalt complexes performed with high activities of up to 1.2 脳 10⁷ g (mol of Co)^鈭? h^鈥? in ethylene polymerization, which represents one of the most active cobalt-based catalytic systems in ethylene reactivity. These biphenyl-bridged bis(imino)pyridylcobalt precatalysts exhibited higher activities than did their mononuclear bis(imino)pyridylcobalt precatalyst counterparts, and more importantly, the binuclear precatalysts revealed a better thermal stability and longer lifetimes. The polyethylenes obtained were characterized by GPC, DSC, and high-temperature NMR spectroscopy and mostly possessed unimodal and highly linear features.