Selective ethylene oligomerization with chromium complexes bearing pyridine-phosphine ligands : influence of ligand structure on catalytic behavior
Selective ethylene oligomerization with chromium complexes bearing pyridine-phosphine ligands : influence of ligand structure on catalytic behavior
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DOI：
10.1021/om5003683
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发表时间：
2014-07
期刊：
影响因子：
2.8
通讯作者：
Yun Yang;Joanna Gurnham;Bo-ping Liu;R. Duchateau;S. Gambarotta;I. Korobkov
中科院分区：
文献类型：
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作者：
Yun Yang;Joanna Gurnham;Bo-ping Liu;R. Duchateau;S. Gambarotta;I. Korobkov
合成了一系列含吡啶-膦配体的铬配合物，并考察了它们在乙烯齐聚反应中的催化行为。溶剂甲苯和甲基环己烷的选择对所有这些配合物的催化活性都有显著的影响。通过修饰影响配体咬合角和柔韧性的膦取代基，引入了配体体系的变化。已经证明，配体结构的微小差异不仅可以导致催化活性的显着变化，而且还可以导致对α-烯烃的选择性和低聚产物的分布。配体PYCH2N(Me)PiPr2与CrCl3(THF)3结合，可选择性地进行乙烯三聚和四聚反应，得到1-己烯和1-辛烯，具有良好的总选择性和高纯度，尽管有少量PE存在。
Chromium complexes bearing a series of pyridine–phosphine ligands have been synthesized and examined for their catalytic behavior in ethylene oligomerization. The choice of solvent, toluene versus methylcyclohexane, shows a pronounced influence on the catalytic activity for all these complexes. Variations of the ligand system have been introduced by modifying the phosphine substituents affecting ligand bite angles and flexibility. It has been demonstrated that minor differences in the ligand structure can result in remarkable changes not only in catalytic activity but also in selectivity toward α-olefins versus polyethylene and distribution of oligomeric products. Ligand PyCH2N(Me)PiPr2, in combination with CrCl3(THF)3 afforded selective ethylene tri- and tetramerization, giving 1-hexene and 1-octene with good overall selectivity and high purity, albeit with the presence of small amounts of PE.