Synthesis and Characterization of Pyrrole-imine [N⁻NP] Nickel(II) and Palladium(II) Complexes and Their Applications to Norbornene Polymerization

Ni(II) and Pd(II) complexes based on N-((1H-pyrrol-2-yl)methylene)-2-(diphenylphosphino)benzenamine were synthesized and characterized. X-ray diffraction studies on complexes 1, 2, and 4 revealed that N, N, P, and halogen atoms coordinated to metal, with distorted square planar geometries in all cases. Upon treatment with modified methylaluminoxane (MMAO), the [N−NP]Ni(II)X complexes are robust and exhibit high activity for the vinyl addition polymerization of norbornene (up to 5.46 × 107 g PNB/mol(Ni)·h·atm).