Ground and Excited State Dipole Moments of Metformin Hydrochloride using Solvatochromic Effects and Density Functional Theory

Semahegn Asemare; Abebe Belay; Alemu Kebede; Umer Sherfedin

doi:10.1007/s10895-023-03355-4

Ground and Excited State Dipole Moments of Metformin Hydrochloride using Solvatochromic Effects and Density Functional Theory

J Fluoresc. 2024 May;34(3):1207-1217. doi: 10.1007/s10895-023-03355-4. Epub 2023 Jul 28.

Authors

Semahegn Asemare¹, Abebe Belay², Alemu Kebede³, Umer Sherfedin³

Affiliations

¹ Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia. semahegnasemare4@gmail.com.
² Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia. abebebelay96@gmail.com.
³ Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia.

PMID: 37505362
DOI: 10.1007/s10895-023-03355-4

Abstract

In this research, the ground (µ_g) and excited (µ_e) state dipole moments of metformin hydrochlorides were determined using Lippert-Mataga, Bakhshiev's, Kawski-Chamma-Viallet, and Reichardt models from fluorescence emission and UV-Vis absorption spectra in various solvents. From solvatochromic effects the calculated excited (µ_e ) dipole moment of metformin hydrochloride were, 8.55 D, 8.34 D, 6.08 D, and 6.40 D using the Lippert-Mataga, Bakhshiev's, Kawski-Chamma-Viallet and Reichardt models respectively. The results also indicated that the dipole moment at the ground state is smaller than the excited state. This is due to solvent polarity having a stronger effect on fluorescence emission than absorption spectra. Similarly, from density functional theory, the calculated ground and excited states dipole moments of metformin hydrochloride using (DFT-B3LYP- 3-21+G*(μ_g= 10.02 D and μ_e= 11.94 D), DFT-B3LYP- 6-31+G (d, p) (μ_g= 8.44 D and μ_e= 10.87 D), and DFT-B3LYP- 6-311+G (d, p) (μ_g= 8.24 D and μ_e= 18.74 D)) analyzed by Gaussian 09W. From the optimized geometry of the molecule, the HOMO-LUMO energy band gap of metformin hydrochloride were computed using DFT [DFT-B3LYP- 3-21+G*(5.51 eV), DFT-B3LYP- 6-31+G (d, p) (5.66 eV), and DFT-B3LYP- 6-311+G (d, p) (5.70 eV)] respectively.

Keywords: DFT; Dipole moment; Excited state; Metformin hydrochloride; Solvatochromic effect.