Flexible Axial Shielding Strategy for Improving Ethylene (Co)polymerization with 8-Cycloalkylnaphthyl α-Diimine Catalysts
作者:Zhou Lu、You Ge、Shengyu Dai
DOI:10.1021/acs.inorgchem.3c01568
日期:2023.9.18
8-arylnaphthyl catalysts, the flexible 8-cyclohexylnaphthyl catalysts exhibited higher activity and produced higher molecular weight polyethylene in ethylene polymerization. Moreover, in nickel-catalyzed ethylene polymerization, the cyclohexyl catalyst produced significantly reduced branched polyethylene, while in palladium-catalyzed ethylene (co)polymerization, the cyclohexyl catalyst produced more
8-芳基或烷基萘基取代基被广泛用作有效的轴向屏蔽策略,用于抑制后过渡金属催化的乙烯(共)聚合以产生高分子量聚乙烯和共聚物中的链转移。本研究设计并合成了两种8-环烷基萘基苊基α-二亚胺配体和相应的四种镍钯配合物,以探讨轴向柔性屏蔽对乙烯(共)聚合的影响。在乙烯聚合中,镍络合物表现出高活性(高达 1.99 × 10 6 g mol –1 h –1)并生成具有高分子量(高达M n = 1075 kg )的轻度支化(34–54/1000 C)聚乙烯。 /mol),而相应的钯配合物表现出中等活性(10 4 g mol –1 h –1水平),产生高分子量(高达M n = 37.6 kg )的高度支化(111–125/1000 C)聚乙烯/摩尔)。这些钯配合物在乙烯/丙烯酸甲酯 (MA) 共聚过程中产生了具有中等插入比 (1.97–5.56 mol%) 的高度支化 (110–123/1000 C) E-MA