1,2,4-triazole-3-thione Schiff bases compounds: Crystal structure, hirshfeld surface analysis, DFT studies and biological evaluation

Abstract

Three novel Schiff base compounds (G1, G2 and G3) were synthesized and characterized by elemental analysis, FT-IR, NMR, and X-ray single crystal diffraction. The crystal structures exhibit both inter- and intra-molecular hydrogen bond interactions, which play significant role in building the self-assemblies. These inter-molecular interactions form the multi-membered pseudo chelate rings and quantify these inter-molecular interactions using Hirshfeld surface analysis. Further, the density functional theory calculations have been performed at the B3LYP method with 6-311G level basis set to optimize the molecular structure. The chemically active of the Schiff bases were identified by the analysis of frontier molecular orbitals and molecular electrostatic potential surface. In addition, the biological activity of compounds were tested against five fungi, and the result showed that compounds G1 exhibited the excellent activity to Wheat gibberellic with EC50 value of 2.864 mg/L than that of Fluconazole (EC50 = 16.79 mg/L).