Six-coordinated half-metallocene catalyst for ethylene polymerization and its mechanism study

• Six-coordinated half-metallocene containing 8-hydroxyquinoline ligands was prepared. • Excellent ethylene polymerization activity and thermal stability was achieved. • Theoretical simulation evaluated possibility of the catalyst and gave the mechanism. • The capture of intermediates validated the proposed mechanism. The demand for catalysts capable of enabling olefin polymerization at elevated temperatures to meet industrial requirements continues to grow. Among emerging candidates, novel six-coordinated half-metallocene catalysts, which combine the advantages of both metallocenes and non-metallocenes, show promise due to their polymerization performance and thermal stability. Despite this potential, the polymerization mechanism of six-coordinated half-metallocenes with one chloride ligand has not been clarified yet and theoretical calculation of new catalysts in olefin polymerization is an indispensable means for catalyst design and mechanism research. Herein, we present the synthesis and application of a six-coordinated half-zirconocene catalyst that exhibits outstanding polymerization activity under high-temperature conditions. Besides, we elucidate the polymerization process through a combination of theoretical studies and experimental validations. Furthermore, the chain transfer reaction during the polymerization was analyzed by the characterization of polymer.