Structural Elucidation of Sulfur Derivatives of Benzimidazoles by Density Functional Calculations, and Vibrational and NMR Spectral Analyses
- *Corresponding Author:
- Ahmet Altun
Department of Genetics and Bioengineering
Department of Physics, Fatih University
Buyukcekmece, Istanbul 34500, Turkey
E-mail: [email protected]
Received date: January 06, 2016; Accepted date: January 22, 2016; Published date: January 25, 2016
Citation: Altun A, Azeez N (2016) Structural Elucidation of Sulfur Derivatives of Benzimidazoles by Density Functional Calculations, and Vibrational and NMR Spectral Analyses. Pharm Anal Acta 7:459. doi:10.4172/2153-2435.1000459
Copyright: © 2016 Altun A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The room temperature structural as well as vibrational (IR and Raman) and NMR (1H and 13C) spectral studies have been performed on 1-methyl-benzimidazole-2-thione, 2-(methylthio)benzimidazole, and 1-methyl-2- mercaptobenzimidazole tautomers at B3LYP/6-311++G** level of theory. 1-methyl-benzimidazole-2-thione is the most stable tautomer with significant energetic separations than the other two tautomers and with too high transition barriers to the other tautomers. This suggests that 1-methyl-benzimidazole-2-thione is the main species at the room temperature. Comparison of experimental and calculated room temperature vibrational and NMR spectra suggests the presence of the 2-(methylthio)benzimidazole and 1-methyl-2-mercaptobenzimidazole tautomers in the solid and solution phases as minor species.