2960-43-2Relevant academic research and scientific papers
Ethylene Tetramerisation: A Structure-Selectivity Correlation
Makume, Boitumelo F.,Holzapfel, Cedric W.,Maumela, Munaka C.,Willemse, J. Alexander,van den Berg, Jan A.
, p. 2308 - 2315 (2020/11/03)
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.
Ethylene trimerisation and tetramerisation catalysts with polar-substituted diphosphinoamine ligands
Overett, Matthew J.,Blann, Kevin,Bollmann, Annette,Dixon, John T.,Hess, Fiona,Killian, Esna,Maumela, Hulisani,Morgan, David H.,Neveling, Arno,Otto, Stephanus
, p. 622 - 624 (2007/10/03)
Chromium-based catalyst systems with polar-substituted diphosphinoamine ligands are selective for either trimerisation or tetramerisation of ethylene, depending on the position of the polar groups on the aryl rings. The Royal Society of Chemistry 2005.
Ethylene tetramerization: A new route to produce 1-octene in exceptionally high selectivities
Bollmann, Annette,Blann, Kevin,Dixon, John T.,Hess, Fiona M.,Killian, Esna,Maumela, Hulisani,McGuinness, David S.,Morgan, David H.,Neveling, Arno,Otto, Stefanus,Overett, Matthew,Slawin, Alexandra M. Z.,Wasserscheid, Peter,Kuhlmann, Sven
, p. 14712 - 14713 (2007/10/03)
Linear α-olefins, such as 1-hexene and 1-octene, are important comonomers in the production of linear low-density polyethylene (LLDPE). The conventional method of producing 1-hexene and 1-octene is by oligomerization of ethylene, which yields a wide spectrum of linear α-olefins (LAOs). While there exists several processes for producing 1-hexene via ethylene trimerization, a similar route for the selective production of 1-octene has so far been elusive. We now, for the first time, report an unprecedented ethylene tetramerization reaction that produces 1-octene in selectivities exceeding 70%, using an aluminoxane-activated chromium/((R2)2P)2NR1 catalyst system. Copyright
Steric activation of chelate catalysts: Efficient polyketone catalysts based on four-membered palladium(II) diphosphine chelates
Dossett,Gillon,Orpen,Fleming,Pringle,Wass,Jones
, p. 699 - 700 (2007/10/03)
Palladium(II) complexes of ligands of the type Ar2PCH2-PAr2 and Ar2PN(Me)PAr2 (Ar = ortho-substituted phenyl group) are very efficient catalysts for copolymerisation of CO and C2H4/su
