DFT studies on physicochemical properties and spectral data of 2-thiophene carboxylic acid thiourea derivatives

The rapid development of drug resistance and also the unsatisfactory status of actual treatment of bacterial and fungal infections make it necessary the existence of new active drugs. In this work, new synthesized thiourea derivatives compounds with pharmaceutical important applications was studied. The general chemical formula of the 2-thiophene carboxylic acid thiourea derivative is down below presented.

N-(p-"R"phenyl)-N’-(2-thenoyl)-thiourea, "R" = -Cl, -Br, -I, -CH3, -OCH3

Such compounds have antimicrobial activity against bacterial and fungal strains. Moreover, they come to offer significant advantages in future treatment strategies [1, 2]. In this research, Density Functional Theory (DFT) calculations was used and the five molecules was described in 6-311G(d,p) basis set, [3]. The optimized molecular structure and the energy of individual molecular orbitals were predicted for thioureide derivatives. For studied molecules, electronic properties such as ionization potential, electron affinity, and electronic excitation energies were calculated and compared in order to establish the beneficial traits of this possible future pharmaceuticals. Also, by DFT the vibrational frequencies, thermodynamic properties and NMR Chemical Shifts of molecules were predicted. To show how this calculation method matches well with the experimental data, we compared the FT-IR experimental data of the thioureide derivatives with the calculated frequencies of the proposed molecules. We found the candidates of which experimental FT-IR spectra are well matched with DFT calculation. Based on these computations, we obtained properties and key molecular descriptors related to chemical reactivity and spectral behavior. The obtained results were compared and discussed.