文献类型：期刊文献

英文题名：Switchable ethylene tri-/tetramerization with high catalytic performance: Subtle effect presented by P-alkyl substituent of PCCP ligands

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

机构：[1]East China Univ Sci & Technol, Key Lab Adv Mat, 130 Mei Long Rd, Shanghai 200237, Peoples R China; East China Univ Sci & Technol, Inst Fine Chem, Sch Chem & Mol Engn, 130 Mei Long Rd, Shanghai 200237, Peoples R China

年份：2022

卷号：415

起止页码：95

外文期刊名：JOURNAL OF CATALYSIS

收录：;EI(收录号：20224212973976);WOS:【SCI-EXPANDED(收录号:WOS:000894211900005)】；

基金：Acknowledgements 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：Ethylene trimerization; Ethylene tetramerization; Electron -rich ligands; Diphosphine ligand; Chromium(III) catalysts

摘要：Electron-rich Ph2PC(R") = CHPRR' ligands with a P-alkyl group were prepared, and, in conjunction with chromium, showed very high activities in ethylene tri-/tetramerization, leading to, in most cases, a very low PE selectivity of <= 0.1 wt%. The electronic property of ligands has a remarkable influence on the cat-alytic activity: the stronger the r-donor ability, the higher the activity. Dialkyl phosphine ligands show a stronger r-donor ability, and thus exhibited higher activities than their mixed alkyl/Ph phosphine coun-terparts. Reducing the ligand steric bulk could convert the selectivity from predominant trimerization into mixed tri-/tetramerization with 1-octene:1-hexene ratio of >1 without compromising high com-bined 1-C6/1-C8 selectivity (>90 wt%). Furthermore, the ligands with a dialkyl phosphine showed high low-temperature activity at 25 degrees C with a relatively high 1-C8 selectivity. Notably, under a lower pressure of 20-30 bar, using PPhiPr-PCCP 7 showed almost no formation of PE with high activity and selectivity.(c) 2022 Elsevier Inc. All rights reserved.