Suyun Jie

Ethylene polymerization promoted by nickel complexes

The nickel complexes are of special relevance to catalysis for ethylene oligomerization and polymerization. Beyond the famous commercial SHOP process for ethylene oligomerization, among recent progress of nickel catalysts, various nickel complexes containing different ligands such as the bidentate and tridentate ligands are of interest. In contrast to the importance of hetereogeneous catalysis, the homogeneous catalyst is a small share for polyolefins, while the well-defined complexes affect the microstructure of the resultant polyolefin. The nickel catalysts often perform ethylene activations for inner olefins and the branched polyethylene with broad or bimodal molecular weight distribution. The catalytic behavior will be affected by adaptation of ligands coordinating around the nickel center. In addition, the auxiliary ligand Ph3P can improve the catalytic activity by one order of magnitude, and its active center can be confirmed through isolating and characterizing the reliable intermediate.

2,9-disubstituted 1,10-phenanthroline nickel complexes: Syntheses, characterization, and their ethylene oligomerization

Nickel complexes 1–4 ligated with 2,9-disubstituted-1,10-phenanthroline were synthesized and characterized by FT-IR spectra and elemental analysis. The molecular structure of complex 2 was confirmed by X-ray crystal diffraction analysis. Activated with methylaluminoxane (MAO), those complexes showed moderate activities for ethylene oligomerization.

Vinyl Polymerization of Norbornene over Supported Nickel Catalyst

Abstract The nickel(II) complex was immobilized onto spherical MgCl 2 , and performed norbornene polymerization in the existence of MAO. Spherical polymer particle morphology was observed without reactor fouling.