Chemical reactions usually involve the conversion of reactants to products by
overcoming an energetic barrier. Most commonly, this process can be assisted by adding energy through heat (thermochemistry), light (photochemistry) or electric current (electrochemistry).
The fourth option is to overcome the reaction barrier through application of mechanical work, termed mechanochemistry. This method has received much attention from the scientific community in the last decade. Both theoretical and experimental studies have been performed, demonstrating the ability of mechanochemistry to activate reactions, with a strong focus on ringopening
reactions. The vast majority of studies have focused on unimolecular reactions involving
bond-rupture, which is very intuitively activated by the application of tensile stress. However, bimolecular reactions, which often involve bond formation as well as rupture, have received much less attention. In this thesis, we seek to change this by undertaking an in-depth study of
mechanochemical activation of addition reactions to carbon-carbon double bonds, which involve the formation of two single bonds while the double bond becomes a single bond. We observe that large barrier changes can be induced by applying external force to reactions of this type, and the magnitude of these changes can be controlled by the choice of alkene substrate. By studying the
changes induced in the geometry of the substrate, we are able to begin explaining the origins of the barrier reduction effect. In addition, by studying the contributions to the barrier change from mechanical work and the contributions from geometry changes, we discover that steric hindrance to a reaction can play a very significant role in the mechanochemical activation of the reaction. / Thesis (Master, Chemistry) -- Queen's University, 2010-11-29 10:43:04.945
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/6207 |
| Date | 29 November 2010 |
| Creators | CARVER, Benjamin Samuel |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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