Vibrational analysis of ethionamide by using quantum chemical calculations and infrared and raman techniques

In this research, for Ethionamide molecule which is used as a drug in the treatment of tuberculosis, structural and vibrational analysis have been performed using Density Functional Theory (DFT) in theoretical calculations and experimentally by using Infrared and Raman spectrometers. The optimized structures have been obtained by scanning the dihedral angles that can mostly affect the structure of the molecule. Harmonic wavenumbers of the molecule have been calculated and these wavenumbers have been improved by "dual scaling factor" method. With the help of these improved wavenumbers, assignments of the bands in FT-IR and FT-Raman spectra have been carried out.