Synthesis, spectroscopic (13C/1H-NMR, FT-IR) investigations, quantum chemical modelling (FMO, MEP, NBO analysis), and antioxidant activity of the bis-benzimidazole molecule

Abstract

In the current study, we first synthesized the molecule 1,2-Bis(2-benzimidazolyl)-1,2-ethanediol, called C1. The structural properties of C1 were explored by spectroscopic investigation (FT-IR and NMR (1H and 13C)) and computational study using density functional theory (DFT) calculation at B3LYP functional and 6-311++G(d,p) basis set in the gaseous phase and DMSO solvent for the first time. The results of the theoretical calculations were compared with experimental studies and the analysis of the results of optimized parameters of molecular geometry, infrared vibrational frequencies, and 1H and 13C NMR chemical shifts for the structure of the main molecule by B3LYP/6-311++G(d,p) in the gas phase revealed mutual agreement between the experimental and computational data. Furthermore, global reactivity properties, frontier molecular orbitals (FMOs) analysis, molecular electrostatic potential (MEP), and natural bond orbital (NBO) characteristics were evaluated to specify the reactivity properties of the title compound using the same level. The antioxidant activity of the studied compound was also investigated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and the results revealed that it has good inhibition of 42.9% at the concentration of 1 mg/mL which can give an idea about the biological activity of the molecule C1.