Vanadium(V) Complexes Bearing Bidentate Phenoxy‐Phosphine Ligands and Their High Performance Toward Ethylene Homopolymerization

A new series of imido-vanadium(V) complexes bearing bidentate phenoxy-phosphine ligands was synthesized in high yields and fully characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. These complexes were systematically evaluated as efficient catalysts for ethylene polymerization. Among them, complex C1 exhibited exceptional activity, up to 446.5 × 10⁶ g_PE (mol_V)^-1·h^-1, along with excellent thermal stability (120°C), long catalytic lifetime (120 min), and broad solvent compatibility. The produced polyethylene samples spanned moderate to ultra-high molecular weights, with a maximum of 160.4 × 10⁴ Da. Systematic structure-activity-polymer investigations revealed that both steric and electronic variations on ligand critically tune catalytic behavior and polymer properties, underscoring the effectiveness of phenoxy-phosphine framework and providing valuable insights for the rational design of high-performance polyolefin catalysts.