The photophysical properties of fluorescent molecules are investigated theoretically using computational methods, including Hartree-Fock and density functional theory (HF/DFT) models. The observed UV-Visible spectra and related photophysical properties are interpreted using energy values from the ground-state geometry. From the optimized structure excited-state geometry is calculated for further analysis. The structure-property relationship of the fluorescent molecule is analyzed, and theoretical data will be validated against the experimental data. In our present study, the photophysical properties of 3-hydroxy-4-pyridine carboxaldehyde (HINA) are studied theoretically in the gas phase. Using DFT calculation with 6-311++G(d,p) basis set, the ground state geometry and potential energy surface are calculated. In addition, the Time-Dependent Density Functional Theory (TD-DFT) method is used to calculate the excited state geometry of the molecule, and finally, the computed results are compared with experimental data.
Saha et al. (2026) studied this question.