Electronic effect regulated ethylene polymerization and copolymerization of phosphorus phenol nickel catalysts

In recent years, phosphorus phenol nickel catalysts with excellent polar monomer copolymerization performance have flourished. A series of phosphorus phenol nickel catalysts based on adjusting spatial hindrance have been designed and synthesized for ethylene polymerization and copolymerization. In this paper, a series of phosphorus phenol nickel catalysts with different para electronic effects have been designed from the perspective of electronic effects, and the effects of these phosphorus phenol nickel catalysts with different electronic effects on ethylene polymerization and copolymerization have been studied. And we found that these nickel catalysts with para electron donating groups have higher catalytic activity (the highest activity can reach 6.2 x 106 gPE molNi-1 h-1) and prepared polymers with higher molecular weight (molecular weight up to 4.9 x 105 gPE molNi-1) compared to electron withdrawing groups. We synthesized a series of phosphorus phenol nickel catalysts with metal para electron withdrawing (-F, -CF3) or electron donating groups (-MeO, -tBu), and we found that these catalysts with para electron donating groups have higher catalytic activity and prepared polymers with higher molecular weight compared to electron withdrawing groups image