The synthesis and characterization of the first aluminum- and gallium-bridged [1]chromarenophanes, [1]vanadarenophanes and [1]molybdarenophanes are described; these compounds belong to a class of compounds referred to as [1]metallacyclophanes. [1]Metallacyclophanes are strained, ring-tilted complexes that have a propensity to undergo ring-opening polymerizations (ROPs). On the basis of using bulky, intramolecularly coordinating ligands, the [1]metallacyclophanes described within have been synthesized and characterized. By exploring known transition-metal catalyzed ROP methodologies, a serendipitous discovery has been made. The gallium-bridged [1]molybdarenophane undergoes ring-opening reactions catalyzed by sigma donors such as thf and triethylphospine or by pi donors such as 1,5-cyclooctadiene. Known transition-metal catalyzed ROP methodologies proved to be unsuccessful with the aluminum- and gallium-bridged [1]metallarenophanes, possibly due to steric overprotection.<p>
The synthesis and characterization of the first [1.1]metallarenophanes is described. By utilizing ligands with dimethylamine-donor functionalities, aluminum- and gallium-bridged unstrained [1.1]chromarenophanes and [1.1]molybdarenophanes have been isolated. Gallium-bridged [1.1]metallarenophanes have been determined to be Class II compounds through investigations by cyclic voltammetry. Aluminum-bridged [1.1]metallarenophanes can not be successfully characterized by electrochemical measurements because of their acute sensitivity towards oxygen and moisture. All isolated [1.1]metallarenophanes adopt anti conformations in the solid state.
Several new reactive aluminum, gallium and indium and compounds have been prepared that incorporate bulky donor ligands.<p>
All new compounds have been characterized by NMR spectroscopy, X-ray crystallography, mass spectrometry and elemental analysis. When comparing solid-state structures of [1]metallarenophanes, some generalizations can be made. For a given [1]metallarenophane gallium-bridged compounds are always more tilted when compared to their respective aluminum-bridged compound for reasons that still remain unknown. If the bridging element is kept constant, the tilt angles are found to increase in the order of Mo > V > Cr for the [1]metallarenophanes, which can be attributed directly to their respective metallic radii.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-11092008-103005 |
| Date | 26 November 2008 |
| Creators | Lund, Clinton Laine |
| Contributors | Urquhart, S. G., Majewski, M., Moewes, A., Macdonald, C., Müller, J,, Foley, S. R. |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-11092008-103005/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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