Selective Ethylene Oligomerization Catalyzed by the Chromium Complex Bearing N-Tetrahydrofurfuryl PNP Ligand

通过胺基锂盐分离的方法合成了一种未有报道过的N-四氢糠基PNP配体E.; E分别与CrCl_3(THF)_3和Cr(CO)_6反应生成化合物[{Ph_2PN(CH_2OC_4H_7)PPh_2}CrCl_2(mu-Cl; )]_2(1)和[Ph_2PN(CH_2OC_4H_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/Cr; Cl_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%.The N-tetrahydrofurfuryl diphoshinoamine (PNP) ligand (E) was synthesized by means of two-step salt elimination reactions where separation of the two kinds of the aminyl lithium salts for the respective reactions is necessary for obtaining a high yield of E. The ligand reacted with CrCl3(THF)(3) and Cr(CO)(6) to give P,P-chelation complexes [{Ph2PN(CH2OC4H7)PPh2} CrCl2(mu-Cl)](2) (1) and [Ph2PN(CH2OC4H7)PPh2] Cr(CO)(4) (2), respectively. Complexes E, 1 and 2 were characterized by spectroscopy and elemental analysis, of which complex 2 was further confirmed by X-ray crystallography. Upon activation with methylaluminoxane (MAO) or AlEt3, the catalyst systems including 1, 2, E/CrCl3(THF)(3), E/Cr(acac)(3) and E/CrCl2(THF)(2) were investigated. The best catalytic activity was achieved by 15.9 kg (product)/g (Cr)circle h in which a selectivity of 63.6% for 1-C-8 was obtained.National Natural Science Foundation of China [21473142, 21673191];; Innovative Research Team Program [IRT_14R31

茂金属催化剂体系及其丙烯聚合性能调控

国内聚丙烯的生产基本上使用传统的Ziegler-Natta催化剂,国外已经使用茂金属催化剂.茂金属催化剂生产的聚丙烯提升了产品性能,市场需求份额逐年增加,国内需要开发茂金属催化剂并拓展工业应用.茂金属催化剂与传统的Ziegler-Natta催化剂相比,结构类型丰富,反应调控能力强,可以催化生成结构多样的聚丙烯.以茂金属催化剂的发展为主线,探讨催化剂结构对反应性能的影响;分析体系中多种因素如温度、压力、催化剂浓度、助剂等对反应活性的调控;讨论催化反应机理.中国石化茂名石化公司基金;;聚烯烃催化技术与高性能材料国家重点实验室基金;;上海市聚烯烃催化技术重点实验室基金(Nos.201501-PT-C01-005,沪CXY-2015-003,16DZ2270800,16DZ2290700);;国家自然科学基金(Nos.21473142,20673191);;教育部创新团队基金(No.IRT_14R31)资助项目~

Advances in Selective Ethylene Oligomerization Based on [PNP]-Ligand Chromium Catalysts

乙烯选择性三聚和四聚催化反应为制备1-己烯和1-辛烯提供了重要途径.在报道和披露的众多结构和组成的催化剂体系中,我们选择[PnP]配位骨架的铬催化剂体系,对其发展和应用进行了综述.论文以结构与催化性能的关联性为主线,阐述[PnP]骨架以及n和P上取代基的电子和立体空间效应对催化性能的影响.从目前的研究态势来看,[PnP]配位骨架的铬催化剂体系在乙烯选择性齐聚生产1-辛烯等线性α-烯烃方面具有发展潜力.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.聚烯烃催化技术重点实验室基金(No.12DZ2260400); 国家自然科学基金(No.21473142); 教育部创新团队(No.IRT_14R31)资助项目~