当前位置:
X-MOL 学术
›
ChemPlusChem
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Ethylene Tetramerisation: A Structure‐Selectivity Correlation
ChemPlusChem ( IF 3.4 ) Pub Date : 2020-09-29 , DOI: 10.1002/cplu.202000553 Boitumelo F. Makume 1, 2 , Cedric W. Holzapfel 1 , Munaka C. Maumela 1, 2 , J. Alexander Willemse 2 , Jan A. Berg 2
ChemPlusChem ( IF 3.4 ) Pub Date : 2020-09-29 , DOI: 10.1002/cplu.202000553 Boitumelo F. Makume 1, 2 , Cedric W. Holzapfel 1 , Munaka C. Maumela 1, 2 , J. Alexander Willemse 2 , Jan A. Berg 2
Affiliation
The effect of ethylene tetramerisation ligand structures on 1‐octene selectivity is well studied. However, by‐product formation is less understood. In this work, a range of PNP ligand structures are correlated with the full product selectivity and with catalyst activity. As steric bulk on the N‐substituent increases, the product selectivity shifts from >10 % to < 3% of both C6 cyclics and C16+ by‐products. 1‐Octene peaks at ca. 70%. Thereafter, only 1‐hexene increases. Similar selectivity changes were observed for ortho‐Ph‐substituted PNP ligands. The C10‐14 selectivity was less affected by the ligand structure. The ligand effect on the changes in selectivity is explained mechanistically. Lastly, an increase in ligand steric bulk was found to improve catalyst activity and reduce polymer formation by an order of magnitude. It is proposed that steric bulk promotes formation of cationic catalytic species which are responsible for selective ethylene oligomerisation.
中文翻译:
乙烯四聚反应:结构选择性相关
乙烯四聚配体结构对1-辛烯选择性的影响已得到很好的研究。但是,对副产物的形成了解较少。在这项工作中,一系列的PNP配体结构与整个产品的选择性和催化剂的活性有关。随着N取代基上空间位阻的增加,产物的选择性从C6环和C16 +副产物的> 10%转变为<3%。1-辛烯峰约于 70%。此后,仅1-己烯增加。对邻有相似的选择性变化Ph取代的PNP配体。C10-14选择性受配体结构的影响较小。机械地解释了配体对选择性变化的影响。最后,发现配体空间体积的增加可改善催化剂活性并将聚合物形成减少一个数量级。提出了空间体积促进阳离子催化物质的形成,所述阳离子催化物质负责选择性的乙烯低聚。
更新日期:2020-10-13
中文翻译:
乙烯四聚反应:结构选择性相关
乙烯四聚配体结构对1-辛烯选择性的影响已得到很好的研究。但是,对副产物的形成了解较少。在这项工作中,一系列的PNP配体结构与整个产品的选择性和催化剂的活性有关。随着N取代基上空间位阻的增加,产物的选择性从C6环和C16 +副产物的> 10%转变为<3%。1-辛烯峰约于 70%。此后,仅1-己烯增加。对邻有相似的选择性变化Ph取代的PNP配体。C10-14选择性受配体结构的影响较小。机械地解释了配体对选择性变化的影响。最后,发现配体空间体积的增加可改善催化剂活性并将聚合物形成减少一个数量级。提出了空间体积促进阳离子催化物质的形成,所述阳离子催化物质负责选择性的乙烯低聚。