Synthesis, structural and spectroscopic studies of two new benzimidazole derivatives: A comparative study

• Published in: Journal of molecular structure Vol. 1130; pp. 46 - 54
• Main Authors: Saral, Hasan, Özdamar, Özgür, Uçar, İbrahim
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.02.2017
• Subjects: 1H and 13C NMR; Benzimidazole; Characterization; DFT calculations; FT-IR; Characterization; FT-IR; 1H and 13C NMR; Benzimidazole; DFT calculations
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2016.10.013

In the present work, structural and spectroscopic studies on 1-Methyl-2-(2′-hydroxy-4′-chlorophenyl)benzimidazole (1) and 1-Methyl-2-(2′-hydroxy-4′-methoxyphenyl)benzimidazole (2), have been carried out extensively by X-ray diffraction, HRMS, UV–Vis, FT-IR and 1H and 13C NMR spectroscopy. The crystal structure of both compounds is stabilized by OH⋯N hydrogen bond and π-π interactions. Contrary to compound 1, the skeleton of compound 2 is considerably deviated from the planarity probably caused by intermolecular hydrogen bonding. The experimental results were compared to the theoretical ones, obtained at DFT level. Ground state geometry, electronic structure, vibrational and NMR spectra have been performed using the B3LYP functional with the 6-31 G(d,p) basis set. It was observed that the bond distances and angles in the both compounds were in good with those of the experiment. The energetic behaviors of the both compounds in methanol solvent were examined using by time-dependent DFT (TD-DFT) method by applying the polarizable continuum model (PCM). Isotropic chemical shifts (13C and 1H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. The HOMO and LUMO analyses were used to elucidate information regarding charge transfer within the molecule. [Display omitted] •Two novel benzimidazole compounds were synthesized.•Single crystal studies have been carried out.•Theoretical calculations under DFT were performed.•Investigation of thermal stability of the synthesized compounds was done.