You are cordially invited to attend the seminar organized by the Department of Chemistry.
Title: Photophysical and Chiroptical Properties of Coumarin and Tetracyanoquinodimethane (TCNQ) Derivatives: Determining the Absoloute Configuration of Chiral Amines.
Speaker: Prof. Dr. Akın Akdağ, Department of Chemistry, Middle East Technical University
Date: May 14, 2024, Tuesday
Time: 12:30 (GMT +3)
Location: SB-Z14 (Department Seminar Room)
Abstract:
Coumarin is a widely used chromophore. There are numerous studies where coumarin unit has been used as sensors for various species. Coumarin light interaction was also found to be very sensitive to the substituents on coumarin. Besides being good light absorbing unit, the chromophore showed chiroptical properties through chirality transfer. Coumarin-3-carboxylic acid could easily be synthesized, and modifed from the carboxylic acid part with amino acids. This study resulted in not only the chirality transfer observation on CD, but it was also found that side chain conformation effects were observed on CD signal.
Due to the complicated nature of observed CD signals for coumarin derivatives, we decided to focus on a new and simple chromophore, tetracyanoquinodimethane (TCNQ) which has been facilitated for its good electron acceptor feature in the literature. Furthermore, when TCNQ was treated with primary amines, the amines substitute two cyano groups to get DADQ compounds. Depending on the absolute configration of the amines, CD signals were observed in the chromophore absorbing region: the CD signals were negative for R-amines, and positive for S-amines. This led us to determine the absolute configration of amines easily.
As a result, these two chromophores can be used for determination of absolute configration of primary amines. In this talk, I will discuss about our results on these subjects.
Short Biography of the Speaker:
Prof. Dr. Akın Akdağ graduated from Middle East Technical University in 1997 and got his Master’s degree from the same institution in 1999. After completing his Master’s degree, he obtained his PhD at Auburn University, United States in 2005 with his work on the synthesis and conformational analysis of purine nucleoside analogs for antiviral purposes under the supervision of Prof. Stewart W. Schneller. Following that, he worked as a postdoc at Auburn University until 2005 and at the University of Colorado, Boulder between 2007 and 2011. In 2011, he worked as a scholar at the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic before he attended Middle East Technical University as a faculty member in 2012. His current research interests focus on the intersection of organic synthesis and physical organic chemistry.