Physicochemical Characterization of the Loganic Acid-IR, Raman, UV-Vis and Luminescence Spectra Analyzed in Terms of Quantum Chemical DFT Approach

Adam Zając; Jacek Michalski; Maciej Ptak; Lucyna Dymińska; Alicja Z Kucharska; Wiktor Zierkiewicz; Jerzy Hanuza

doi:10.3390/molecules26227027

Physicochemical Characterization of the Loganic Acid-IR, Raman, UV-Vis and Luminescence Spectra Analyzed in Terms of Quantum Chemical DFT Approach

Molecules. 2021 Nov 20;26(22):7027. doi: 10.3390/molecules26227027.

Authors

Adam Zając¹, Jacek Michalski¹, Maciej Ptak², Lucyna Dymińska¹, Alicja Z Kucharska³, Wiktor Zierkiewicz⁴, Jerzy Hanuza²

Affiliations

¹ Department of Bioorganic Chemistry, Faculty of Production Engineering, Wroclaw University of Economics and Business, 118-120 Komandorska str., 53-345 Wrocław, Poland.
² Institute of Low Temperature and Structure Research, 2 Okólna str., 50-422 Wrocław, Poland.
³ Department of Fruit, Vegetable and Plant Nutraceutical Technology, Wrocław University of Environmental and Life Sciences, 37 Chełmońskiego str., 51-630 Wrocław, Poland.
⁴ Faculty of Chemistry, Wrocław University of Science and Technology, 27 Wybrzeże Wyspiańskiego str., 50-370 Wrocław, Poland.

Abstract

The molecular structure and vibrational spectra of loganic acid (LA) were calculated using B3LYP density functional theory, the 6-311G(2d,2p) basis set, and the GAUSSIAN 03W program. The solid-phase FTIR and FT-Raman spectra of LA were recorded in the 100-4000 cm^-1 range. The assignment of the observed bands to the respective normal modes was proposed on the basis of the PED approach. The stability of the LA molecule was considered using NBO analysis. The electron absorption and luminescence spectra were measured and discussed in terms of the calculated singlet, triplet, HOMO, and LUMO electron energies. The Stokes shift derived from the optical spectra was 20,915 cm^-1.

Keywords: IR; Raman spectra; Stokes shift; UV-Vis measurements; loganic acid; luminescence; molecular structure; quantum chemical DFT calculations.