Date of Award
2009
Degree Type
Thesis
Degree Name
Doctor of Philosophy
Program
Chemistry
Supervisor
Dr. Paul J. Ragogna
Second Advisor
Dr. Mark S. Workentin
Third Advisor
Dr. Oleg Semenikhin
Abstract
The development of novel ionic liquids (ILs) predominantly arises from the resourceful design of an organic salt, which contains a functionality capable of performing a targeted application. Such task-specific ionic liquids (TSILs) conserve the quintessential properties that define a salt as an ionic liquid, that is; a melting point below 100 °C, a high thermal stability and a large liquid range. The benefits attributed to the additional functionality culminate in a superior and unique cooperative system. There are limited reports on the generation of phosphonium containing TSILs and therefore this dissertation highlights significant progress in expanding the collection of such functionalized salts and their applications. The synthesis of a series of phosphonium ionic liquids (PILs) containing various degrees of fluorine loadings were prepared and comprehensively characterized. The highly fluorinated phosphonium ionic liquids (FPILs) were uniquely suited for the preparation of coatings on roughened silver substrates. These films exhibited contact angles greater than 150° placing the ionic liquid coatings within the superhydrophobic regime, an unprecedented application of ionic liquids as functional materials. Further alterations to incorporate a thiol terminated substituent facilitated the covalent tethering of the FPIL to the surface and enhanced the durability of the film. Preliminary investigations towards preparing FPILs adapted as pendant functionalities along a polymethacrylate backbone, fosters the progression of developing potentially more advanced ionic liquid materials with tunable mechanical properties. The development of phosphonium TSILs was not limited to surface applications, as PILs which participate in chemical transformations were prepared. A tethered transition metal complex-PIL resulted in a catalyst, which given the predisposed ionophilic nature, selectively remained isolated in the IL reaction medium. As a result, improved catalyst activity, recovery and product isolation were observed in Suzuki- Miyaura and Heck reactions. Furthermore, maleimide modified PILs were employed as templates to generate TSILs that readily react with thiol and amine substituents via Michael addition. A multitude of functionalized PILs were prepared and comprehensively investigated. Such materials found potential utility in fields extending across several disciplines within chemistry, identifying PILs as a competitive alternative to the traditional nitrogen based analogues.
Recommended Citation
Tindale, Jocelyn Joan, "The Development of New Paradigms for Phosphonium Ionic Liquids" (2009). Digitized Theses. 4212.
https://ir.lib.uwo.ca/digitizedtheses/4212