Theoretical modeling of optical spectra of N(1) and N(10) substituted lumichrome derivatives
Denisa Cagardová *, Jan Truksa a, Martin Michalík, Jan Richtár b, Jozef Krajčovič c, Martin Weiter d, Vladimír Lukeš
Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37 Bratislava, Slovakia
a Faculty of Chemistry, Brno University of Technology, Purkyňova 118, CZ-612 00 Brno, Czech Republic
b Faculty of Chemistry, Brno University of Technology, Purkyňova 118, CZ-612 00 Brno, Czech Republic
c Faculty of Chemistry, Brno University of Technology, Purkyňova 118, CZ-612 00 Brno, Czech Republic
d Faculty of Chemistry, Brno University of Technology, Purkyňova 118, CZ-612 00 Brno, Czech Republic
E-mail: * denisa.cagardova@stuba.sk
Abstract: A systematic study of (7,8-dimethylated) alloxazine, isoalloxazine, and their derivatives with substituted N(1) and N(10) positions was conducted using the density functional theory. The main aim of this work was the direct investigation of substituent effect on the molecular structure. Furthermore, HOMED aromaticity indices were calculated to describe the scope of the geometry changes. Frontier molecular orbitals of reference alloxazine, isoalloxazine, and lumichrome derivatives were discussed by means of changes in their shape and energy levels. Photophysical properties were analyzed by determination of optical transition energies using the TD-DFT method. Obtained results were compared with previously published experimental data.
Keywords: Aromaticity index; vertical excited transitions; excited states; fluorescence; lumichrome; alloxazine
Acta Chimica Slovaca, Vol. 13, No. 2, 2020, pp. 1—9, DOI: 10.2478/acs-2020-0017