Exploring the non-covalent interactions, vibrational and electronic properties of 2-methyl-4-hydro-1,3,4-triazol-thione-5 in different solutions

In this study, the optimal geometry and vibrational assignments of 2-methyl-4-hydro-1,3,4-triazol-thione-5, one of the triazole derivatives, were analysed by the DFT approach and vibrational spectroscopy. PED values were calculated, and vibrational assignments were determined. Experimental results showed that interactions between 2-methyl-4-hydro-1,3,4-triazol-thione-5 and solvent (acetone, acetonitrile, dioxane, and DMF) molecules lead to a red shift of the N-H stretching vibrational band. The computations were performed at the B3LYP/6-311++G(d,p) functional set. The molecular electrostatic potential surface was used to distinguish between electrophilic and nucleophilic regions. The reactivity of the molecular complexes was determined by examining their frontier molecular orbitals. Topological investigations revealed the existence of N-H…N and N-H…O-type hydrogen bonds between 2-methyl-4-hydro-1,3,4-triazole-thiol-5 and solvent molecules. The red-shift of the N-H stretching band and H-bond strength between solute–solvent molecules are in the order of acetonitrile, acetone, dioxane, and DMF.