Spectrophotometric and Computational Insights into 2-Ethylimidazole-3,5-Dinitrobenzoic Acid Complex: BSA Interaction and Antimicrobial Activity

Abstract

The new charge transfer (CT) complex of 2-Ethylimidazole (2-EI) and 3,5-dinitrobenzoic acid (3,5-DNB) has been synthesized and Fourier Transform Infrared Spectroscopy (FTIR) and UV-Vis spectroscopy, combined with computational approaches such as density functional theory (DFT), time-dependent density functional theory (TD-DFT), and molecular docking, have been employed to analyze it. The FTIR spectra of the CT complex suggest the transfer of electrons by displaying a new band in the CT spectra, it is further confirmed by SC-XRD analysis demonstrating N+__ H…..O– bonding having a bond length of 2.648 Å. Moreover, the Benesi – Hildebrand plot and equation validate the 1:1 stoichiometry of the synthesized complex and various physical parameters such as ionization potential (ID), energy of interaction (ECT), oscillator strength (f), resonance energy (RN), and free energy (ΔGo) have been determined by using UV-visible spectroscopy. Additionally, the anti-bacterial and anti-fungal biological activity of the CT complex as well as its protein binding properties were examined. The CT complex has been shown to have the ability to interfere with bacterial cell membranes or metabolic processes, which may have bacteriostatic or bactericidal effects. Similarly, by interfering with essential cellular functions or rupturing fungal cell membranes, CT complex may have antifungal activity against a variety of fungal species. To investigate how the synthesized CT complex attached to the BSA protein (PDB ID: 3V03), molecular docking experiments were conducted. Computations using density functional theory (DFT) were also carried out at the theoretical level of B3LYP/6-311G++. The optimized geometry, the HOMO→LUMO electronic energy gap, and a molecular electrostatic potential map of the synthesized CT complex were all analyzed.