一种吡啶二亚胺类铁催化剂的合成及乙烯低聚研究

设计并合成了一种新型吡啶二亚胺类铁配合物 ,该配合物配体中将氟取代基和甲基取代基结合在一起 ,用于乙烯齐聚活性可以达到 10 7g molFe·h ,产物中 90 %以上是 1 丁烯 ,1 己烯和 1 辛烯等低碳数α 烯烃 .低聚反应温度对低聚活性和低聚物分布有很大影响 ,随着反应温度的提高 ,齐聚活性降低 ,低聚物明显向低碳数分布移动 .随着Al Fe的增加 ,低聚活性先迅速增加 ,在Al Fe为 10 0 0时达到最大 ,然后又迅速降低 ;低聚物的分布基本不受Al Fe的影响 .比较了几种具有相似结构的化合物及其低聚性能与新合成的催化剂 ,讨论了配合物结构与低聚活性和低聚物性能之间的关系 .合适的邻位取代基位阻和取代基电子效应是决定催化剂活性和低聚物分布的主要因素 .

SYNTHESIS OF A NOVEL BIS(IMINO)PYRIDYL IRON COMPLEX AND ITS OPPLECATION IN OLIGOMERIZATION OF ETHYLENE

A novel 2,6\|bis(imino) pyridyl iron complex bearing flouoro and methyl substituents has been synthesized and used for ethylene oligomerization.The activity of this complex could reach 1 8×10\+7 g/mol Fe\5h when used for ethylene oligomerization,and most of the resulting products(>90%) are low\|molar\|mass oligomers,such as 1\|butene,1\|hexene and 1\|octene.The catalytic activities are influenced greatly by reaction temperature.With increase of reaction temperatures,the activities decrease rapidly and more low\|molecular\|weight products are produced.The distribution of obtained oligomers is almost invariant with the Al/Fe molar ratio,but the catalytic activities increase rapidly at first and then decrease because of the deficient protection provided by small steric bulk of bluoro at ortho position of aryl rings.As a result the chain transfer to MAO occurs more easily.Another three complexes have also been synthesized for comparison.Adapted ortho \|and para \|substituents on aryl rings are the main effects on oligomerization activities and distributions of oligomers for 2,6\|bis(imino) pyridyl iron complexes.