文献类型：期刊文献

英文题名：Ethylene Tri-/Tetramerization Catalysts Supported by Phenylene- Bridged Mixed Alkyl/Aryl Diphosphine Ligands

作者：Kong, Weihuan[1,2];Ma, Xufeng[1,2];Zuo, Jing[1,2];Zhao, Xing[1,2];Zhang, Jun[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Inst Fine Chem, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China

年份：2023

卷号：42

期号：8

起止页码：651

外文期刊名：ORGANOMETALLICS

收录：;EI(收录号：20231513882669);WOS:【SCI-EXPANDED(收录号:WOS:000967544200001)】；

基金：ACKNOWLEDGMENTS Financial support from the Fundamental Research Funds for the Central Universities (222201717003) and the National Natural Science Foundation of China (22071055) is greatly acknowledged.

语种：英文

外文关键词：Aromatic compounds - Catalyst activity - Chromium compounds - Electronic properties - Ligands - Phosphorus compounds - Temperature

摘要：Cr(III) complexes supported by phenylene-bridged diphosphine ligands with P-alkyl substitution were prepared and evaluated in ethylene tri-/tetramerization. The ligand steric and electronic properties have significantly influenced the catalytic activity. The Cr complex 1 based on a bulky PCy2 phosphine ligand L1 having a stronger sigma-donor ability exhibited the highest activity, which is more reactive than its PPh2 counterpart 8. The selectivity toward ethylene tri-/tetramerization is mainly determined by the steric property of ligands. Reducing the ligand steric bulk switched the selectivity from predominant trimerization into mixed tri-/tetramerization. 1 achieved a high 1-hexene selectivity of 82.5 wt % with a 1-octene selectivity of 9.7 wt %, while 4 based on L4 bearing a less bulky PPhCy group gave a considerable 1-octene selectivity of 43.3 wt % with a very high activity of 1874 kggCr-1 h-1. 1 also exhibited a high activity even at a relatively low temperature of 40 degrees C, while both 4 and 5 based on a PPh(alkyl) diphosphine ligand gave poor activities at 40 degrees C. More importantly, these Cr complexes showed a very low PE selectivity of <0.1 wt %.