Studies on utilization of new fluorescent compounds in chiral discrimination

2020
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.

Suggestions

How Web 2.0 tools can be integrated in early childhood education?
Tunga, Yeliz; Aytekin, Merve; Kaplan, Göknur (null; 2018-05-04)
Recently, considering the fact that technology use is inevitable for everyone due to increasing ease of access to technological devices such as mobile phones and tablet PCs along with the necessity of digital literacy in the 21st century; technology use in early childhood education is no longer a taboo. In fact, the question whether technology should be used in early childhood education classrooms has shifted to how it can be used in a more developmentally appropriate way in these classrooms. However, the c...
Context of use of home use medical devices: a study on the identification of contextual factors of CPAP devices
Aydın, Merve; Börekçi, Naz Ayşe Güzide Z.; Department of Industrial Design (2014)
World population is getting older and technology is advancing rapidly over the last decades. At the intersection of these changes, there is a growing desire to provide more effective healthcare to the elder population with the help of improving technology. Medical devices have started to become miniaturized, simplified and affordable enough to find their way out of hospitals into homes. This situation has affected the design considerations on medical devices due to the change of the user groups and product ...
A study of lightweight cryptography
Çamur, Zeliha; Doğanaksoy, Ali; Department of Cryptography (2020)
Technology is evolving rapidly and with technology, the internet is also changing. People used to use internet to connect to each other. But with the changes in recent years, the internet is starting to be used more to connect devices to each other. These devices can range from powerful computing devices, such as desktop computers and tablets, to resource contrained devices, such as RFID tags and sensor networks. When it comes to these constrained devices, conventional cryptographic algorithms fail to provi...
Neural-network-based process controller design and on-line application to fluidised bed combustion
Altug, S; Tulunay, E (1996-08-01)
Intelligent on-line control has been increasingly popular in the past decade. In this paper, a neural-network-based controller utilising a modified error term in the backpropagation algorithm is presented for the purpose of on-line control of the nonlinear time-varying fluidised bed combustion (FBC) process. The aim of the modification of the error term was to improve the controller performance by enabling the neural network to perform a 'negative hysteresis' action. The general design steps, alterations in...
A New search engine ontology for visually impaired users
Akkaya, Ezgi; Karagöz, Pınar; Betin Can, Aysu; Department of Information Systems (2015)
In today’s world, semantic technology is getting more and more important day by day. After Web 3.0, semantic infrastructure has become a must for internet based systems. In this thesis, we have focused on the semantic basis of search engines. Google, Yahoo, Yandex and Bing are the most popular search engines. All of them have a semantic structure, however the semantics have been developed according to the users who have not any visual impairment. In this study, search engine ontology has been developed acco...
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.