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Cocatalyst Influence in Selective Oligomerization: Effect on Activity, Catalyst Stability, and 1-Hexane/1-Octene Selectivity in the Ethylene Trimerization and Tetramerization Reaction

Citation

McGuinness, DS and Rucklidge, AJ and Tooze, RP and Slawin, AMZ, Cocatalyst Influence in Selective Oligomerization: Effect on Activity, Catalyst Stability, and 1-Hexane/1-Octene Selectivity in the Ethylene Trimerization and Tetramerization Reaction, Organometallics, 26, (10) pp. 2561-2569. ISSN 0276-7333 (2007) [Refereed Article]

DOI: doi:10.1021/om070029c

Abstract

The trimerization and tetramerization of ethylene to 1-hexene and 1-octene with a Cr/PNP/AlEt 3 catalyst system, in combination with a variety of cocatalysts, has been investigated. The cocatalysts B(C 6F 5) 3 (1), Al(OC 6F 5) 3 (2), [(Et 2O) 2H][Al(OC 6F 5) 4] (3), [Ph 3C][Ta(OC 6F 5) 6] (4), (Et 2O)Al{OCH(C 6F 5) 2} 3 (5), (Et 2O)-Al{OC(CF 3) 3} 3 (6), [Ph 3C][Al{OC(CF 3) 3} 4] (7), [Ph 3C][AlF{OC(CF 3) 3} 3] (8), [Ph 3C][{(F 3C) 3CO} 3Al-F-A1{OC(CF 3) 3} 3] (9), and [Ph 3C][CB] 11H 6Br 6] (10) have been evaluated. The relative selectivity to 1-hexene and 1-octene obtained shows a strong dependence on the nature of the cocatalyst, and a range of selectivities from <5% C 8 (90% C 6) to 72% C 8 have been observed. The stability of several cocatalysts toward AlEt 3 has been studied, and the poor performance of 1 and 2 is linked to degradation of the cocatalyst through ethyl group exchange with AlEt 3. In contrast, the [Al{OC(CF 3) 3} 4] - anion in 7 is much more stable and gives rise to a highly active and longer lived catalyst. The overall productivity and selectivity of the catalyst is dependent upon both cocatalyst stability and the nature of the anion present, and a reason for this effect has been suggested. Selectivity control by the cocatalyst has been ascribed to interaction of the anion with the active Cr center. © 2007 American Chemical Society.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Physical Chemistry (incl. Structural)
Research Field:Catalysis and Mechanisms of Reactions
Objective Division:Manufacturing
Objective Group:Industrial Chemicals and Related Products
Objective Field:Organic Industrial Chemicals (excl. Resins, Rubber and Plastics)
Author:McGuinness, DS (Dr David McGuinness)
ID Code:50974
Year Published:2007
Web of Science® Times Cited:80
Deposited By:Chemistry
Deposited On:2007-08-01
Last Modified:2009-12-15
Downloads:0

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