安徽大学陈敏团队报道了半不稳定α-二亚胺镍催化烯烃聚合。相关研究成果于2024年12月10日发表在国际顶尖学术期刊《中国化学》。

对于配位插入烯烃聚合，新型过渡金属催化剂的开发引起了该领域的广泛关注。

该文中，研究人员设计了一系列以氧原子为邻近基团的半不稳定α-二亚胺镍催化剂。这些影响乙烯（共）聚合过程的镍配合物（Ni1-Ni4）的空间位阻和氧原子数可以调节。

与没有氧原子的对应物相比，引入氧原子可以提高Ni2在乙烯聚合过程中的热稳定性。对于乙烯与极性单体的共聚过程，研究实现了更高的催化活性（1.4×10⁶g·mol^-1·h^-1）和极性单体掺入率（1.2mol%）。然而，在该项工作中，由于氧原子和镍催化中心之间的相互作用，具有四个氧原子的Ni4在乙烯聚合中没有活性。

该项工作中的半不稳定效应，为提高α-二亚胺镍催化剂在烯烃聚合中的稳定性提供了一个例子。

附：英文原文

Title: Hemilabile α-Diimine Nickel Catalyzed Olefin Polymerization

Author: Muhammad Asadullah Khan, Yue Liu, Wenmin Pang, Ao Chen, Min Chen

Issue&Volume: 2024-12-10

Abstract: For coordination-insertion olefin polymerization, the development of novel transition-metal catalysts has drawn extensive attention in this field. In this contribution, we designed a series of hemilabile α-diimine nickel catalysts bearing oxygen atom as neighboring group. The steric hindrance and oxygen atom number of these nickel complexes (Ni1—Ni4) could be adjusted, which influenced ethylene (co)polymerization processes. The introduction of oxygen atoms could enhance the thermal stability during ethylene polymerization for Ni2 compared to the counterpart without oxygen atoms. And for the copolymerization process of ethylene with polar monomers, higher catalytic activity (1.4 ×106 g·mol1·h1) and polar monomer incorporation ratio (1.2 mol%) were achieved. However, Ni4 with four oxygen atoms in this work was not active in ethylene polymerization due to the interaction between the oxygen atom and nickel catalytic center. The hemilabile effect in this work presented an example to enhance the stability of the α-diimine nickel catalysts in olefin polymerization.

DOI: 10.1002/cjoc.202400881

Source: https://onlinelibrary.wiley.com/doi/full/10.1002/cjoc.202400881