Research Progress of Iron Catalysts with N,N,N‐tridentate Ligands for Ethylene Polymerization

Abstract Some iron complexes are found to be effective catalysts of ethylene polymerization and have become a research hotspot due to their advantages of high activity, good thermal stability, and mild reaction conditions. Compared with other systems, iron catalysts bearing N,N,N‐tridentate ligand have good comprehensive performance in catalyzing ethylene polymerization. This review article focuses on changes in the framework of bis(imino)pyridyl ligand and the effect of different substituents on the catalytic performance of ethylene polymerization (activity, molecular weight, thermal stability, etc.) since 2019. Despite significant achievements, many opportunities and possibilities are yet to be fully addressed, and a brief outlook on the future of issues should be focused on is provided.