Studies on utilization of new fluorescent compounds in chiral discrimination

Tan, Duygu
In modern age, time is becoming an increasingly valuable parameter. Advances in science and technology are triggered by using time more effectively. The reflection of this in chemistry is towards developing computer-aided setups that allow performing multiple experiments at the same time and developing analysis techniques that can give results within a short time period. For many years, scientists have been trying to modify some spectroscopic techniques (mass, nmr, fluorescence, etc.) to develop alternative methods that will give faster results. Among these techniques, fluorescence spectroscopy is the most remarkable and open to development in recent years. For this purpose, fluorescence spectroscopy is used in various fields such as DNA folding, protein dynamics, drug detection, and enantiomeric excess determination in asymmetric reactions. Among these applications, asymmetric reactions are of great importance for the pharmaceutical industry, as they allow chiral substances to be obtained in high purity. However, a widely used method for the practical determination of the results of such reactions has not yet been developed. Studies on this subject have been growing rapidly in recent years. In this dissertation, in order to contribute to the applications of fluorescence spectroscopy in the field of chiral recognition, new chiral fluorescence sensors based on coumarin, naphthalene and 7,7,8,8-tetracyanoquinodimethane (TCNQ) were developed and characterized by NMR, HRMS and FTIR techniques. Fluorescence studies have been performed to distinguish tartaric acid, α-methylbenzyl amine, 1-phenyl ethanol and 2-butanol enantiomers with these new fluorescence sensors by fluorescence technique. From these new chiral sensors synthesized, coumarin-derived ones did not show selectivity against any of the above- mentioned substances, while they were successful in sodium and potassium determination and showed selectivity towards sodium. Naphthalene derivative sensor shows affinity for all carboxylic acids; however, it has not been able to separate the enantiomers of those carboxylic acids. Our TCNQ based sensors showed selectivity against α-methylbenzyl amine enantiomers. For all sensors, experimental results were supported by theoretical calculations. This dissertation covers all the details of synthetic, spectroscopic, chromatographic and theoretical studies.
Citation Formats
D. Tan, “Studies on utilization of new fluorescent compounds in chiral discrimination,” Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Chemistry., Middle East Technical University, 2020.