초록 |
Nickel complexes based on coordination models of ligands such as bidentate N∧N and tridentate N∧N∧N have attracted great attention since which show good catalytic activities towards ethylene polymerization/oligomerization. We would like to report the synthesis and ethylene polymerization /oligomerization behavior of nickel complex based on peptide ligand, which have attracted considerable attention in recent years due to their non-toxicity, biocompatibility. A kind of peptide based Ni(II) complex (general formula [ZN=C(An)-C(An)=NZ](NiBr2)x, Z=(4-NHR-3,5-C6H2(CH3)2)2CH(4-C6H5), An=acenaphthenequinone, R=polypeptides) was synthesized and showed high activity for ethylene oligomerizations (106g oligomer/(mol Ni.bar.h) ) when activated with ethyl aluminium sesquichloride (EAS) in toluene. The effects of reaction temperature and EAS on the catalytic activity and the distribution of resulting oligomer were investigated. |