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AMO/QO Physics Seminar

"Light sensitive azobenzene and its derivatives, experimental and computational studies"

Dr. Mohammadreza Rezaee
Department of Physics and Astronomy
University of Tennessee


Azobenzene and its derivatives are photo-responsive and their cis/trans geometry can be mechanically changed upon irradiation with light with specific wavelength, making them excellent candidates for molecular photo-switching, photonic devices and a variety of biophysical applications.

Gas phase ion chemistry studies are a rich and promising field and an important area of chemical, molecular and atomic physics. We studied azobenzene and several of its derivatives using several experimental techniques in addition to comprehensive ab initio computational investigations. We used the energy resolved collision induced dissociation technique to study the chemical bonding and electronic structure of these molecules negative and/or positive ions. The fragment ions which were detected in the mass spectrum were then studied computationally. In some cases these are interesting structures which have not been studied before. By doing so we experimentally measured the bond dissociation energies and compared them with the result of the quantum chemistry computations. We also performed other experiments such as Raman spectroscopy, NMR spectroscopy and UV-V is spectroscopy to experimentally study the electronic structure of these molecules. We utilized state of the art high accuracy multi-level computational calculations to study thermochemical properties of these molecular structures. We calculated electron affinities and compared the results of different techniques such as density functional theory and perturbative methods to compare their performances.

The comparison of these highly accurate computational results with the experimental results provides an accurate benchmark for use with different molecules and ions. By comparing our experimental results for electron affinities and bond dissociation energies with theoretically obtained results, we have shown that ab initio computations can yield accurate results. The information we provided regarding to the electronics structure and the thermochemical properties of the azobenzene and several of its derivatives and their ions, can be helpful in the future applications of these light sensitive molecules.

Wednesday, September 16, 2015
IQSE 578, 2:00 PM
Mitchell Physics Building

Department of Physics and Astronomy
Texas A&M University

Host: Dr. Hans Schuessler