The most ubiquitous polymer, polyethylene (PE), is produced either through a radical-initiated process or, more commonly, through a coordination/insertion process employing early transition metal catalysts, particularly titanium- and chromium-based systems. These oxophilic early metal catalysts are not functional-group-tolerant and thus cannot be used to synthesize copolymers of ethylene and polar vinyl monomers such as alkyl acrylates and vinyl acetate. Such PE copolymers have enhanced properties relative to PE and are made through radical polymerization processes, requiring exceptionally high pressures and temperatures. Copolymerizations of polar vinyl monomers with ethylene using more functional group-tolerant late metal catalysts potentially offer an attractive alternative for generating such value-added copolymers since ligand variations may provide more control of polymer microstructures and milder reaction conditions would apply. This Account describes our efforts, particularly through detailed mechanistic studies, to probe and develop this potential using Pd(II) and Ni(II) α-diimine catalysts.

中文翻译：

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使用Ni和Pdα-二胺催化剂探索乙烯/极性乙烯基单体共聚

最普遍存在的聚合物，聚乙烯（PE），是通过自由基引发的方法生产的，或更常见的是通过使用早期过渡金属催化剂（尤其是钛和铬基体系）的配位/插入过程生产的。这些亲氧的早期金属催化剂不具有官能团耐受性，因此不能用于合成乙烯和极性乙烯基单体如丙烯酸烷基酯和乙酸乙烯酯的共聚物。这种PE共聚物相对于PE具有增强的性能，并且是通过自由基聚合方法制备的，需要极高的压力和温度。极性乙烯基单体与乙烯使用更耐官能团的后期金属催化剂的共聚潜在地为产生这种增值共聚物提供了一种有吸引力的替代方法，因为配体的变化可以提供对聚合物微结构的更多控制，并且适用较温和的反应条件。该帐户描述了我们的努力，尤其是通过详细的机理研究，以探索和开发使用Pd（II）和Ni（II）α-二亚胺催化剂的潜力。