The synthesis of asymmetrical anilinotropone nickel and palladium complexes for olefin polymerization

For the Coordination-insertion olefin polymerization, the development of high-performance transition-metal catalysts is always the key issue and extensive efforts have been made in this field. In this contribution, we designed several asymmetrical anilinotropone nickel and palladium catalysts. Compared to palladium complex, the nickel catalysts exhibited high activity in ethylene polymerization. The topology microstructure of polyethylene could be modulated by different polymerization temperature. The anilinotropone nickel catalysts Ni2 and Ni3 in this work demonstrated higher thermolability, generating polyethylene with higher molecular weight (up to 285.9 kg mol−1). Moreover, these nickel systems also promoted the copolymerization of ethylene with norbornene-type polar monomers (NB–COOMe, NB-OAc), which demonstrated great polar group tolerance in this system. The generated copolymer exhibited high molecular weight (up to 93.1 kg mol−1) and high polar monomer incorporation ratio (up to 6.9 mol%). The design of asymmetrical anilinotropone catalysts in this work presented a unique form in olefin polymerization and may attract wide application interests in metal catalysis areas.