Alternating α-Olefin Distributions via Single and Double Insertions in Chromium-Catalyzed Ethylene Oligomerization
| Autor: | James D. Nobbs, Robert Malinowski, Sarah K. Y. Ho, George J. P. Britovsek, David S. McGuinness, Craig T. Young, Andrew J. P. White, Atanas K. Tomov, Prabhjot K. Saini, Juan J. Chirinos, Mark R. J. Elsegood |
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| Rok vydání: | 2016 |
| Předmět: |
MECHANISM
Benzimidazole Ethylene Chemistry Organic chemistry.chemical_element DONOR 010402 general chemistry 0305 Organic Chemistry 01 natural sciences Catalysis Inorganic Chemistry chemistry.chemical_compound Chromium TRIMERIZATION 0399 Other Chemical Sciences Polymer chemistry 0302 Inorganic Chemistry Chemistry Inorganic & Nuclear Physical and Theoretical Chemistry TETRAMERIZATION Olefin fiber Science & Technology 010405 organic chemistry Ligand Organic Chemistry REACTIVITY CHAIN GROWTH 0104 chemical sciences Chemistry POLYMERIZATION chemistry Physical Sciences METAL-COMPLEXES LIGANDS Amine gas treating Bar (unit) |
| Zdroj: | Organometallics. 36:510-522 |
| ISSN: | 1520-6041 0276-7333 |
| Popis: | The catalytic oligomerization of ethylene with chromium-based complexes containing bis(benzimidazolemethyl)amine (BIMA) ligands results in alternating distributions of linear α-olefins (LAOs). Extremely high activities are obtained (>100 000 g mmol–1 h–1 bar–1) with N-alkyl-substituted BIMA ligands, whereas bulky groups on the central nitrogen or alternative central donors result in much lower activities. Variations in the ligand backbone, as well as methylation of the benzimidazole units, lead to reduction in activity. The alternating LAO distributions have been mathematically analyzed using second-order recurrence relations. The shape of the distributions is affected by ethylene pressure (1–4 bar) and by the cocatalyst to some degree. On the basis of the results and analysis presented herein, we propose that the alternating behavior originates from the ability of these chromium BIMA catalysts to undergo single as well as double ethylene insertion reactions. A minor second distribution ( |
| Databáze: | OpenAIRE |
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