The design, synthesis and mesomorphic properties of discotic liquid crystals

Stackhouse, Philip Jeffrey

Abstract

Discotic liquid crystal research is now more than 30 years old, however it is still early days compared with the well-established area of calamitic liquid crystal research which dates back for more than a century. Since the 1990’s there has been great deal of interest in discotic liquid crystal research, due to applications such as discotic compensation films for enhancing liquid crystal display (LCD) viewing angles and exciting new potential applications such as organic semi-conductors and photovoltaics.The work contained in this thesis can be broken down into three major areas: investigation of synthetic methodologies of hexasubstituted triphenylene-based discotic liquid crystals, examination of structure-property relationships within novel triphenylene-based discotic liquid crystalline materials, and the design and mesomorphic properties of novel disc-shaped molecular architectures.The investigation of the synthetic methodologies of triphenylene-based liquid crystals examined two main areas of the synthesis of triphenylene-based discotic materials: iodination reactions to generate valuable intermediates, and the oxidative strategies and methods for the generation of hexasubstituted triphenylenes. These investigations have revealed that careful control over reaction conditions can offer great selectivity in the synthesis of halogenated intermediates for the synthesis of triphenylene-based liquid crystals and that electron rich intermediate species offer the greatest scope for the synthesis of hexasubstituted triphenylenes in good yield and purity.The determination of structure-property relationships within triphenylene-based discotic liquid crystals has examined various peripheral substituents and various near-core modifications to the conventional discotic liquid crystal.A small number of novel spiral-shaped materials have been synthesised, which have revealed interesting mesomorphic properties. These materials have shown the ability to self-organise in such a manner as to fill free space around central disc units so as to generate columnar mesophases in materials which would not otherwise be expected to exhibit mesomorphism.

Citation

Stackhouse, P. J. (2008). The design, synthesis and mesomorphic properties of discotic liquid crystals. (Thesis). University of Hull. Retrieved from https://hull-repository.worktribe.com/output/4208629

• Thesis Type: Thesis
• Deposit Date: Aug 15, 2011
• Publicly Available Date: Feb 22, 2023
• Keywords: Physical science
• Public URL: https://hull-repository.worktribe.com/output/4208629
• Additional Information: Department of Physical Sciences, The University of Hull
• Award Date: Jul 1, 2008