Master of Science (MSc)
Faculty of Science
In this thesis, the synthesis and liquid crystalline properties of a series of novel dibenz[a,c]anthracenes are reported. Specifically, two dibenzanthracenecarboxylate derivatives were prepared and were found not to exhibit a mesophase. In contrast, a series of novel N-substituted dibenzanthracenedicarboximides was also synthesized and found to exhibit broad columnar temperature ranges. Several dibenzanthracenedicarboximides substituted with different alkyl chains on the nitrogen atom were prepared and their mesomorphic temperature ranges were characterized. In general, it was found that having a longer, more flexible alkyl chain on the nitrogen atom resulted in a broadening of the columnar temperature range via a lowering of the melting point transition temperature.
We also prepared a novel electron donor-acceptor liquid crystal by doping a non-mesomorphic hexaalkoxydibenzanthracene with electron-poor trinitrofluorenone. In contrast to the preferred 1:1 molar ratio of donor to acceptor usually demonstrated by charge-transfer liquid crystals, this series was found to prefer a 2:1 molar ratio of donor to acceptor. Several other electron donor-acceptor series using structurally related dibenzanthracene and dibenzophenazine derivatives were found to exhibit similar behaviour suggesting that, instead of an alternating donor-acceptor stacking arrangement, more of a sandwich-like 2:1 stacking arrangement may be preferred.
Psutka, Katie M., "Synthesis and Characterization of Coloumnar Mesophases of Novel Substituted Dibenzanthracenes and Their Donor-Acceptor Mixtures" (2014). Theses and Dissertations (Comprehensive). 1665.