Zhang Yan-Ping, Li Wei-Wei, Li Bai-Xiang, Mu Hong-Liang, Li Yue-Sheng
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Dalton Trans. 2015 Apr 28;44(16):7382-94. doi: 10.1039/c5dt00074b.
Phosphino-phenolate neutral nickel catalysts 1-3/B(C6F5)3, without the help of any organoaluminum compound, were found to be efficient catalytic systems for norbornene polymerization and its copolymerization with norbornene derivatives. The amount of B(C6F5)3 required for achieving a high efficiency (3 equiv.) was markedly lower compared to previous reports, and high molecular weight polymers were obtained (>10(6) g mol(-1)). Efficient incorporation of polar monomers NBC, NBA, and NBM was also achieved in a controllable fashion, yielding high molecular weight copolymers. Catalysts 1-3 were highly active for ethylene polymerization as single component catalysts, with an activity of up to 10(7) g molNi(-1) h(-1), and catalyst 3 was more readily initiated at lower temperature. Catalysts 1-3 were also efficient in incorporating norbornene (up to 30%) into the polyethylene backbone. Bisligated phosphino-phenolate nickel complex 4 and salicylaldimine complex 5 were also studied for comparison, which further verified the unique performance of catalysts 1-3. Preliminary NMR analyses were conducted to explore the norbornene polymerization mechanism.
在不借助任何有机铝化合物的情况下，膦基酚盐中性镍催化剂1 - 3/B(C6F5)3被发现是用于降冰片烯聚合及其与降冰片烯衍生物共聚的高效催化体系。与之前的报道相比，实现高效率（3当量）所需的B(C6F5)3量显著更低，并且获得了高分子量聚合物（>10(6) g mol(-1)）。极性单体NBC、NBA和NBM也能以可控方式有效引入，得到高分子量共聚物。催化剂1 - 3作为单组分催化剂对乙烯聚合具有高活性，活性高达10(7) g molNi(-1) h(-1)，并且催化剂3在较低温度下更容易引发。催化剂1 - 3还能有效地将降冰片烯（高达30%）引入聚乙烯主链。还研究了双配位膦基酚盐镍配合物4和水杨醛亚胺配合物5以作比较，这进一步证实了催化剂1 - 3的独特性能。进行了初步的核磁共振分析以探索降冰片烯聚合机理。
