Asymmetric PO-type ligands are versatile platforms for palladium and nickel catalyzed ethylene polymerization as well as copolymerization of ethylene with polar monomers. In this work, a series of phosphinoamine phosphoramidate/phosphoramide ligands and the corresponding palladium/nickel catalysts were prepared, characterized and investigated in ethylene polymerization as well as copolymerization of ethylene with various polar monomers. The palladium and nickel complexes exhibited high activities in ethylene (co) polymerization, generating high-molecular-weight polyethylenes and copolymers of ethylene and polar monomers. The introduction of electron-donating substituents in the palladium catalytic system can significantly increase polymer molecular weights while maintaining high ethylene (co)polymerization activities. The less electronic donating substituents in the nickel catalysts led to increased catalytic activities in both ethylene polymerization and copolymerization with polar monomers. These results demonstrate the importance of ligand electronic effect in tuning the properties of nickel and palladium catalysts in ethylene polymerization and copolymerization reactions.

不对称的PO型配体是钯和镍催化的乙烯聚合以及乙烯与极性单体共聚的通用平台。在这项工作中，制备了一系列膦胺氨基磷酸酯/磷酰胺配体和相应的钯/镍催化剂，在乙烯聚合以及乙烯与各种极性单体的共聚中进行了表征和研究。钯和镍配合物在乙烯（共）聚合反应中表现出高活性，生成高分子量聚乙烯以及乙烯与极性单体的共聚物。在钯催化体系中引入给电子性取代基可以显着增加聚合物分子量，同时保持较高的乙烯（共）聚合活性。镍催化剂中电子给体较少的取代基导致乙烯聚合和与极性单体共聚的催化活性增加。这些结果证明了在乙烯聚合和共聚反应中调节镍和钯催化剂性能的配体电子效应的重要性。