Synthesis, characterization, and ethylene polymerization of 1-[2,4-bis(bis(4-fluorophenyl)methyl)naphthylimino]-2-aryliminoacenaphthylnickel bromides: influences of polymerization parameters on polyethylenes

Abstract

A series of 1-[2,4-bis(bis(4-fluorophenyl)methyl)naphthylimino]-2-aryliminoacenaphthylene derivatives (L1–L5) was prepared and used to react with (DME)NiBr₂ to form the title complexes (C1–C5). The organic compounds were characterized by ¹H/¹³C NMR measurements, FT-IR spectra and elemental analysis. Meanwhile, the nickel complexes were analyzed by FT-IR spectra, elemental analysis, and single-crystal X-ray diffraction of the representative complex C1, which indicated a distorted tetrahedral geometry around the nickel center. Upon activation with diethylaluminum chloride (Et₂AlCl), all the title nickel complexes were highly active for ethylene polymerization, resulting in polyethylenes with high molecular weights ranging from 0.86–5.58 × 10⁵ g mol⁻¹ and narrow polydispersity (1.22–1.99). Moreover, significant influences of polymerization parameters on the resultant polyethylenes were examined and are discussed.