Computational investigation of structural and electronic properties of cis and trans structures of fluvoxamine as a nano-drug

Abstract

In this study, geometrical structure, electronic and optical properties, electronic absorption spectra, vibrational frequencies, thermodynamic properties, natural charge distribution and MEP analysis of trans and cis structure of fluvoxamine medicine have been studied by quantum chemical calculations using density functional theory (DFT) and time-dependent DFT (TDDFT) method with the B3LYP hybrid functional and 6-311+G∗∗ basis set. The results of the calculations show that trans structure of fluvoxamine has convenient quantum chemical properties to verify that this structure of the molecule is marked as a medicine. The relative energies of trans and cis structures of fluvoxamine shows that the trans structure is more stable than the cis form with a small energy difference. TDDFT calculations display that trans structure of fluvoxamine has the best absorption properties. The calculated NLO properties confirm that the NLO properties of trans structure of fluvoxamine are higher than the cis structure, and the chemical hardness of the trans structure, is lower than the cis structure that shows that the reactivity and charge transfer of trans-fluvoxamine is higher than cis-fluvoxamine. The MEP maps of trans and cis structures of fluvoxamine illustrate that there are some possible region for electrophilic and nucleophilic reactivity. The calculated thermodynamic parameters are increasing with enhancing temperature. The vibrational frequencies of the two configurations of fluvoxamine demonstrate that both structures of fluvoxamine have practically comparable modes of vibrations, but the trans conformation of fluvoxamine is better in agreement with the experiment.