Synthesis and ethylene oligomerization behavior of trinuclear nickel complex with phosphorus dendrimer
A phosphorus dendrimer with multiple amino groups was synthesized via a two-step reaction with phosphonitrilic chloride trimer and 4-acetamidophenol. The trinuclear nickel complex was subsequently prepared with the phosphorus dendrimer and nickel chloride hexahydrate as starting materials. The structures of the phosphorus dendrimer and the trinuclear nickel complex were characterized by physicochemical and spectroscopic methods. The trinuclear nickel complex based on the phosphorus dendrimer was evaluated as catalyst precursor for ethylene oligomerization using methylaluminoxane (MAO) as an activator. Under the conditions of 0.5 h, 0.9 MPa, 25 °C and Al/Ni molar ratio of 700, the catalytic activity of the trinuclear nickel complex showed a maximum value of 2.31 × 10 5 g/(mol Ni h), and the oligomerization products were mainly low-carbon olefins (C 4 and C 6 ). The ligand structure and the coordination mode showed notable variations in the catalytic activities and the product distribution due to the influence of electronic and steric effects. The catalytic activity of the nickel complex based on the ligand with an aryl backbone was superior to the nickel complex based on the ligand with an alkyl backbone.
危险品化学品经营许可证（带存储）