Chromium Catalysts Based on Tridentate Pyrazolyl Ligands for Ethylene Oligomerization
作者:Fernando Junges、Maria C. A. Kuhn、Ana H. D. P dos Santos、Carlos R. K. Rabello、Christophe M. Thomas、Jean-François Carpentier、Osvaldo L. Casagrande
DOI:10.1021/om070215i
日期:2007.7.30
A set of chromium(III) complexes CrCl3(L) based on tridentate ligands (1, L = bis[2-(3,5-dimethylpyrazolyl)ethyl)]amine; 2, L = bis[2-(3,5-dimethyl-l-pyrazolyl)ethyl]benzylamine; 3, L = bis[2-(3,5-dimethyl-l-pyrazolyl)ethyl] ether; 4, L = bis[2-(3-phenyl-l-pyrazolyl)ethyl] ether; 5, L = bis[2-(3,5-dimethyl-l-pyrazolyl)ethyl] sulfide)) have been prepared and characterized by elemental analysis, ESI-HRMS
一组基于三齿配体(1,L =双[2-(3,5-二甲基吡唑基)乙基]胺的铬(III)络合物CrCl 3(L);2,L =双[2-(3,5-二甲基-1-吡唑基)乙基]苄胺;3,L =双[2-(3,5-二甲基-1-吡唑基)乙基]醚;4,L =双[2-(3-苯基-1-吡唑基)乙基]醚;5,L =双[2-(3,5-二甲基-1-吡唑基)乙基]硫醚))已经被制备和表征通过元素分析,ESI-HRMS,和用于X射线衍射研究3。经甲基铝氧烷(MAO)活化后,这些预催化剂在乙烯低聚反应中显示出高活性(TOF =(3.4-131.0)×10 3(mol乙烯)(mol Cr)-1 h在80°C时为-1),选择性地生产出C 4 -C 14+范围内的α-烯烃。催化性能基本上受配体环境,特别是桥供体原子和反应条件的影响。在优化的条件下([Cr] = 10μmol,80°C,乙烯40 bar,MAO-Cr = 300),预催化剂5的TOF