Comparative study of new chromium-based catalysts for the selective tri- and tetramerization of ethylene. Issue 3 (18th December 2014)

• Record Type: Journal Article
• Authors: Härzschel, Stefan; Kühn, Fritz E.; Wöhl, Anina; Müller, Wolfgang; Al-Hazmi, Mohammed H.; Alqahtani, Abdullah M.; Müller, Bernd H.; Peulecke, Normen; Rosenthal, Uwe
• Is Part Of: Catalysis science & technology. Volume 5:Issue 3(2015:Mar.)
• Page Start: 1678
• Page End: 1682
• Publication Date: 2014-12-18
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c4cy01441c
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Small changes in ligand structure and conditions make a chromium ethylene oligomerization catalyst to switch from 1-hexene to 1-octene selectivity. Abstract : Two new ligands, Ph2 PN(iPr)P(Ph)N( c -Hex)(CH3 ) (2 ) (Ph = phenyl, iPr = isopropyl, c -Hex = cyclohexyl) and Ph2 PN( c -Hex)P(Ph)NEt(CH3 ) (Et = ethyl) (3 ) were synthesized.2 was characterized by X-ray analysis. To compare their applicability with the previously known Ph2 PN(iPr)P(Ph)N(iPr)H (1 ) these ligands were investigated together with chromium(iii )acetylacetonate, different co-catalysts and solvents for the catalytic oligomerization of ethylene. The in situ prepared catalysts proved to be highly active, yielding highly pure 1-octene as the main product and 1-hexene as the main byproduct. It was possible to reach productivities of several hundred kg product per gram chromium and hour, up to almost 65 wt% 1-octene with about 99% purity and overall 1-hexene plus 1-octene yields of more than 85 wt%.