文献类型：期刊文献

英文题名：PCCP ligands with a semi-rigid backbone for chromium-catalyzed selective ethylene tri-/tetramerization

作者：Zhao, Xing[1,2];Xie, Haojie[1,2];Zuo, Jing[1,2];Wang, Jihe[1,2];Zhao, Mei-Xin[1,2];Zhang, Jun[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, 130 Mei Long Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Inst Fine Chem, Sch Chem & Mol Engn, 130 Mei Long Rd, Shanghai 200237, Peoples R China

年份：2025

卷号：15

期号：9

起止页码：2713

外文期刊名：CATALYSIS SCIENCE & TECHNOLOGY

收录：;EI(收录号：20251218084882);WOS:【SCI-EXPANDED(收录号:WOS:001448628000001)】；

基金：We are grateful for financial support from the National Natural Science Foundation of China (22071055) and the Fundamental Research Funds for the Central Universities (222201717003).

语种：英文

外文关键词：Alkylation - Catalysis - Complexation

摘要：A series of semi-rigid PCCP ligands (R '' PhPC( 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 CRR ')CH2PPhR ''') containing a rigid olefinic moiety and a flexible methylene moiety within the ligand backbone was prepared, and their application to chromium-catalyzed selective ethylene tri-/tetramerization has been explored. These PCCP ligands could be easily modified at both the olefinic moiety and two P-substituents. Among the ligands bearing two PPh2 groups, L3, with a phenyl substituent at the olefinic site of the ligand backbone, in combination with chromium exhibited the highest activity (644 kg g-1 Cr h-1) and the highest 1-C6 selectivity, as well as the highest combined 1-C6/1-C8 selectivity at 60 degrees C. Complex 3, based on L3, also exhibited high thermal stability, giving a high activity of 1259 kg g-1 Cr h-1 at 100 degrees C. Complex 4, containing L4 with a PPhCy group adjacent to the rigid olefinic site, showed improved activity compared to its PPh2 counterpart 1. At 80 degrees C, complex 4 exhibited a high combined 1-C6/1-C8 selectivity of 91.0 wt%, with almost no PE formation. The addition of hydrogen was shown to be capable of significantly improving the catalytic performance. In the presence of hydrogen, the catalytic activity increased 2.3-3.2-fold for 3 and 4, giving a very high activity of up to 2160 kg g-1 Cr h-1 with significantly reduced PE formation (0.2 wt%).