The catalytic reaction for the selective ethylene trimerization and tetramerization provides a vital route to the production of 1-hexene and 1-octene. Among the numerous catalysts reported with diverse structures and compositions, we select the [PNP]-ligand based chromium catalysts and focus on illustration on their development and application. This contribution includes seven sections as ethylene (selective) oligomerization catalyst systems, [PNP]-ligand based Cr catalyst system, catalytic mechanism, ethylene oligomerization method, catalytic property, and conclusion and prospect, which will cover almost all of the [PNP]-ligand based Cr catalysts so far studied. In this article, we will mainly discuss the influence on the catalytic property owing to the electronic and/or steric characters of the skeleton as well as the substituents at both N and P atoms of the [PNP]-ligands. In view of the current advances in this field, this [PNP]-ligand based Cr catalyst system is of potencial in application for the production of LAO mainly as 1-octene.

反应生成化合物[{Ph 2 PN(CH 2 OC 4 H 7)PPh 2 }CrCl 2 (μ-Cl)] 2 (1)和[Ph 2 PN(CH 2 OC 4 H 7)PPh 2 ]Cr(CO) 4 (2). 这三个化合物通过谱 学和元素分析表征, 化合物 2 进一步经过 X 射线单晶结构确认. 在甲基铝氧烷(MAO)或其它助剂作用下, 考察了 1、2 以及 E/CrCl 3 (THF) 3 、 E/Cr(acac) 3 、 E/CrCl 2 (THF) 2 催化体系催化乙烯齐聚的性能. 这些体系高选择性地催化乙烯四聚, 最 高活性为 15.9 kg (product)/g (Cr)•h, 1-辛烯的选择性最高可达 63.6%.