Synthesis, spectrophotometric, pharmacology and theoretical investigation of a new electron transfer complex of 8-hydroxyquinoline with oxalic acid in different polar solvents

Abstract

Preparation, characterization, and investigation of a novel organic charge transfer (CT) complex were carried out, with a focus on exploring its antibacterial and antifungal characteristics. Theoretical analysis backs up the experimental findings. CT complex formed was synthesized between 8-hydroxyquinoline (8HQ) and oxalic acid (OA) at RT (room temperature). Different analyses were used to describe the CT complex, including ¹H-NMR, FTIR, TGA/DTA, and UV-vis spectra (in different solvents). These indicate that the CT interaction is linked to proton transfer from OA to 8HQ and the subsequent development of ‘N^+__H^…O^-“ type bonding. On the basis of wave number, the CT complex and reactants are distinguished in FTIR spectra. By using Thermo gravimetric Analysis/Differential Thermal Analysis (TGA/DTA) tests, the thermal stability of complicated and thorough corrosion was examined. Through UV-visible spectroscopy, physical characteristics like E_CT (interaction energy), R_N (resonance energy), I_D (ionization potential), f (oscillator strength) and ΔG (free energy) were calculated. The ε_CT (molar extinction coefficient), the K_CT (formation constant), and additional physical properties of this complex were calculated by the Benesi-Hildebrand equation in order to determine its 1:1 stoichiometry. The biological properties are also supported by theoretical study. The protein, Human Serum Albumin (HSA), is observed to bind with CT complex, as shown by molecular docking and the observed binding energy value is −167.04 kcal/mol. Molecular dynamics (MD) simulation 100 ns run was used to refine docking results and binding free energy was calculated using MM-PBSA. This study introduces a novel CT complex, offering fresh perspectives on molecular interactions.

Communicated by Ramaswamy H. Sarma

Keywords:

• CT complex
• spectrophotometric
• pharmacology
• molecular docking
• MD simulation

Acknowledgements

The authors would like to convey their gratitude to the Department of Chemistry, Faculty of Science, University of Tabuk, Saudi Arabia, for its enthusiastic support of their present endeavors.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.