中文摘要：

综述了近年来PNP配体铬系催化体系催化乙烯选择性三聚和四聚的最新进展，介绍了PNP配体及其与Cr的配合物的合成方法。列举了P上不同取代基的20种PNP配体结构式，以及N上不同取代基的36种PNP配体结构式，比较了PNP铬配合物的乙烯选择性齐聚催化性能。总结了PNP配体乙烯选择性齐聚催化机理，包括金属环催化机理和双金属催化机理。国内外研究结果表明：PNP配体中P和N上取代基的电子效应和空间位阻是影响其催化性能的主要因素。设计合成新型的配体及催化剂对实现工业化乙烯选择性四聚生产1-辛烯以及实现乙烯选择性齐聚合成其他高碳数α-烯烃至关重要。

英文摘要：

The recent developments in the research of chromium catalysts bearing PNP ligands used in selective ethylene oligomerization are summarized, including the synthesis of PNP ligauds and the corresponding Cr complexes. Twenty kinds of PNP ligands structure formulas with different substituent groups attached to P atom, and thirty-six kinds of PNP ligands structure formulas with dif- ferent suhstituent groups attached to N atom are enumerated, and the catalytic performances of selective ethylene oligomerization by chromium catalysts bearing PNP ligands are compared. The catalytic mechanisms of selective ethylene oligomerization by chromium catalysts bearing PNP ligands are reviewed including metallaeycle and bimetal catalytic mechanisms. It is concluded from a lot of research at home and abroad that the electronic and steric hindrance properties of substituents attached to the N and P atoms in PNP ligands significantly affected the catalytic properties. Design and synthesis of novel ligands and catalysts is crucial for the industrialization of ethylene selective tetramerization process to produce 1-octene and the ethylene selective oligomerization synthesis of other high carbon number alpha olefins.