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Ethylene Oligomerization with Cr-NHC Catalysts: Further Insights into the Extended Metallacycle Mechanism of Chain Growth
Citation
McGuinness, DS and Suttil, JA and Gardiner, MG and Davies, NW, Ethylene Oligomerization with Cr-NHC Catalysts: Further Insights into the Extended Metallacycle Mechanism of Chain Growth, Organometallics, 27, (16) pp. 4238-4247. ISSN 0276-7333 (2008) [Refereed Article]
Abstract
The mechanism of ethylene oligomerization with chromium(III) complexes of bis(carbene)pyridine ligands in combination with MAO has been investigated. Oligomerization with mixtures of CH2CH2/ CD 2CD2 reveals that this system produces α-olefins via an extended metallacycle mechanism. Deviation form a Schulz-Flory distribution has been explained on the basis of less favorable product release at the early stages of metallacycle growth (Cr-C4 (±Cr-C6)). Significant amounts of branched olefins (methylidenes) and linear internal olefins are produced at the high catalyst loadings employed in this study, and these result from secondary incorporation of α-olefins into the metallacycle mechanism. Changing the ligand C∧N∧C coordination mode in any way resulted in a sharp loss of activity. In the case of bidentate carbene-pyridine and carbene-thiophene ligands, this is due to a change in the mechanism from metallacycle to linear chain growth. Thus, only those catalysts which support a metallacycle mechanism promote oligomerization with high activity. © 2008 American Chemical Society.
Item Details
Item Type: | Refereed Article |
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Research Division: | Chemical Sciences |
Research Group: | Inorganic chemistry |
Research Field: | Transition metal chemistry |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the chemical sciences |
UTAS Author: | McGuinness, DS (Dr David McGuinness) |
UTAS Author: | Suttil, JA (Mr James Suttil) |
UTAS Author: | Gardiner, MG (Associate Professor Michael Gardiner) |
UTAS Author: | Davies, NW (Associate Professor Noel Davies) |
ID Code: | 52363 |
Year Published: | 2008 |
Web of Science® Times Cited: | 116 |
Deposited By: | Chemistry |
Deposited On: | 2008-06-30 |
Last Modified: | 2009-05-01 |
Downloads: | 0 |
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