能源化学(英文版)

能源化学(英文) ›› 2003, Vol. 12 ›› Issue (2): 98-104.

• Articles • 上一篇    下一篇

Nickel Complexes Bearing Bidentate SchiBase as Ethylene Oligomerization Catalysts

Jianjun Yi, Xugeng Huang, Wei Zhang, Xiaoyu Hong, Zhenhua Jing   

  1. Research Institute of Petroleum Processing, Beijing 914-24, Beijing 100083, China
  • 出版日期:2003-06-30 发布日期:2003-06-30

Nickel Complexes Bearing Bidentate SchiBase as Ethylene Oligomerization Catalysts

Jianjun Yi, Xugeng Huang, Wei Zhang, Xiaoyu Hong, Zhenhua Jing   

  • Online:2003-06-30 Published:2003-06-30

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摘要： Several nickel complexes [N,N]NiBr2, in which [N,N] indicates bidentate nitrogencontaining ligands (1: [N,N]=N-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine (C18H22N2); 2: N-(2,6- diisopropylphenyl)-6-methylpyridine-2-carboxaldimine (C19H24N2); 3: N-(2,4,6-trimethylphenyl)pyridine- 2-carboxaldimine(C15H16N2); 4: N-(2,4,6-trimethylphenyl)-6-methylpyridine-2-carboxaldimine (C16H18- N2) were synthesized. Some of the nickel complexes exhibit high activity for ethylene oligomerization in the presence of an organoaluminum activator. The main factor a ecting the activity and the structure of oligomers is the steric e ect of substituents on [N,N] ligands. Methylaluminoxane (MAO) -activated catalysts showed higher activities and produced oligomers with higher molecular weight than Et2AlClactivated ones. The oligomerization in toluene rather than hexane results in much higher activity, and the oligomers produced in toluene have relatively high molecular weight. With activation of MAO or Et2AlCl, the [N,N]NiBr2 system tended to produce highly branched oligomers with low a-olefin content, but the a-olefin content could be increased by changing the reaction conditions.

关键词: nickel complexes, Schiffbase, ethylene, oligomerization

Abstract: Several nickel complexes [N,N]NiBr2, in which [N,N] indicates bidentate nitrogencontaining ligands (1: [N,N]=N-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine (C18H22N2); 2: N-(2,6- diisopropylphenyl)-6-methylpyridine-2-carboxaldimine (C19H24N2); 3: N-(2,4,6-trimethylphenyl)pyridine- 2-carboxaldimine(C15H16N2); 4: N-(2,4,6-trimethylphenyl)-6-methylpyridine-2-carboxaldimine (C16H18- N2) were synthesized. Some of the nickel complexes exhibit high activity for ethylene oligomerization in the presence of an organoaluminum activator. The main factor a ecting the activity and the structure of oligomers is the steric e ect of substituents on [N,N] ligands. Methylaluminoxane (MAO) -activated catalysts showed higher activities and produced oligomers with higher molecular weight than Et2AlClactivated ones. The oligomerization in toluene rather than hexane results in much higher activity, and the oligomers produced in toluene have relatively high molecular weight. With activation of MAO or Et2AlCl, the [N,N]NiBr2 system tended to produce highly branched oligomers with low a-olefin content, but the a-olefin content could be increased by changing the reaction conditions.

Key words: nickel complexes, Schiffbase, ethylene, oligomerization