Nickel Complexes Bearing 8-Arylimino-7,7-Dimethyl-5,6-Dihydroquinoline:Synthesis, Characterization toward Ethylene Polymerization
N,N-Bidentate nickel complexes have been extensively investigated toward ethylene polymerization.1 Though the 8-arylimino-5,6,7-trihydroquinolylnickel complexes generally showed high activities, interestingly 2-substituted 8-arylimino-5,6,7-trihydroquinolylnickel complexes showed oligomerization2 whilst 8-arylimino-5,6,7-trihydroquinolylnickel complexes (without 2-substituent)showed polymerization.3-5 In addition, due to the double bond C=N linked on the cyclohexane, it was often to observe both presence of the C=N (imino group) linked on the cyclohexane and C-NH (amino group) linked on the fused cyclohexene.To overcome the feasibility of double bond migration, the 7,7-dimethyl-5,6-dihydroquinolin-8-one is prepared to form their imino-derivatives, 6 which were used to react with nickel bromide for the title complexes.Activated with the co-catalysts of either methylaluminoxane (MAO) or ethylaluminiumsesquichloride (EASC), all nickel complexes exhibited high activities towards ethylene polymerization and produced polyethylene waxes with low molecular weights and narrow polydispersities.The fluctuation ranges of polydispersities (1.7-2.0) of obtained polyethylenes are narrow and indicate single-site active species of the catalytic systems, being considered the positive influence of the geometry-constrained organic ligands due to 7,7-dimethyl-substituents preventing any imine-enaminetautomerization.
Chuanbing Huang Shizhen Du Youfu Zhang Wen-Hua Sun
Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences,Beijing 100190, China
国际会议
9th International Symposium on High-Tech Polymer Materials(第9届国际高技术高分子材料学术会议)(HTPM-9)
郑州
英文
101-101
2016-07-11（万方平台首次上网日期，不代表论文的发表时间）