Master of Science (MSc)
Faculty of Science
Dr. Kenneth E. Maly
In this thesis, the synthesis of a series of brominated alkoxy-substituted trinaphthylenes was developed using a nickel-mediated Yamamoto coupling as the main step. Characterization of these compounds led to the discovery of a new set of broad range liquid crystals. They were found to undergo higher order transitions (i.e. glass phases/soft crystals/liquid crystal) via DSC, and also to decompose before reaching an isotropic liquid, as verified via thermogravimetric analysis. Polarized optical microscopy showed a texture characteristic of a columnar hexagonal mesophase. In addition, the aggregation in solution was studied using concentration dependent NMR studies, and the brominated-derivatives were determined to have an association constant 29 times greater than the trinaphthylene precursors. The precursors were newly synthesized via the Yamamoto coupling reaction in moderate yields with a facile purification, however did not show any mesomorphic properties.
In addition, the synthesis of a large starphene bearing long alkoxy chains and ethynyl-TMS groups was attempted. The synthesis of this compound was ultimately unsuccessful, and the challenges are summarized herein. Furthermore, a new method was found in the preparation of tetranaphthylene by simply varying the concentration of the Yamamoto reaction solution.
Bellemore, Vanessa, "The Synthesis of Symmetric Polycyclic Aromatic Hydrocarbons and the Mesomorphic Properties of Their Brominated Derivatives" (2017). Theses and Dissertations (Comprehensive). 1969.
Available for download on Saturday, September 08, 2018