Synthesis, solvent role in TD-DFT (IEFPCM model), fluorescence and reactivity properties, topology and molecular docking studies on sulfathiazole derivative

Abstract

A new class of Schiff base, 4-(butan-2-ylideneamino)-N-(thiazol-2-yl) benzenesulfonamide (EMKTH) was synthesized from sulfathiazole by simple condensation with methyl ethyl ketone. The molecular structure was characterized by infrared, 1H and 13C NMR, and UV–visible spectroscopic studies. These results were compared with theoretical values. Density functional theory (DFT) calculations were performed to determine the structure and reactivity of the molecule. Further, HOMO-LUMO, MEP, and NBO calculations were performed on this system to examine the electronic and chemical properties of this EMKTH system. The UV spectra were analyzed at ambient temperature to determine the electronic absorption maximum using TD-DFT. In the UV study, there was more solvent interaction in the solvent phase than in the gas phase, which is where the maximum wavelength was observed. Docking simulations were performed on the target protein (1W3R) in order to evaluate the binding affinity of EMKTH. It was found that the target protein had a larger energy of −3.99 kcal/mol. The findings showed that there is a significant correlation between the experimental and theoretical values. The molecule's effective charge transfer mechanism, which accounts for its high chemical reactivity, was suggested by a small orbital gap. The synthesized molecule EMKTH exhibited both intra- and intermolecular charge transfer capabilities in line with the NBO results. Analysis of the EMKTH compound's molecular electrostatic potential (MEP) revealed its reactive sites.