摘要
The synthesis and characterization of a novel trinuclear diphosphinoamine ligand 2 are reported. The ligand combined with Cr(III), activated with methylaluminoxane, lead to highly active and long-lifetime catalytic systems for the tetramerization of ethylene to form 1-octene. The effects of reaction temperature, reaction pressure, molar ratio of Al/Cr and bis(diphenylphosphino)amine/Cr on the catalytic activity and product selectivity were studied. Compared with its mononuclear analogue 1, ligand 2 showed a higher catalytic activity and longer lifetime for ethylene tetramerization in the presence of methylaluminoxane as cocatalyst. High molecular weight polyethylene was generated as a by-product with extremely broad molecular weight distributions.
The synthesis and characterization of a novel trinuclear diphosphinoamine ligand 2 are reported. The ligand combined with Cr（III）, activated with methylaluminoxane, lead to highly active and long-lifetime catalytic systems for the tetramerization of ethylene to form 1-octene. The effects of reaction temperature, reaction pressure, molar ratio of A1/Cr and bis（diphenylphosphino）amine/Cr on the catalytic activity and product selectivity were studied. Compared with its mononuclear analogue 1, ligand 2 showed a higher catalytic activity and longer lifetime for ethylene tetramerization in the presence of methylaluminoxane as cocatalyst. High molecular weight polyethylene was generated as a by-product with extremely broad molecular weight distributions.
基金
supported by the National Natural Science Foundation of China (U1162114)
the Program for New Century Excellent Talents in University
the Program for New Century Excellent Talents in Heilongjiang Provincial University(NCET-06-010)
the Science Foundation of Tianjin University of Science & Technology (20090420)
