Single proton intramigration in novel 4-phenyl-3-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)-1H-1,2,4-triazole-5(4H)-thione: XRD-crystal interactions, physicochemical, thermal, Hirshfeld surface, DFT realization of thiol/thione tautomerism

This study reports the synthesis of the novel crystalline 4-phenyl-3-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)-1H-1,2,4-triazole-5(4H)-thione compound in an excellent yield via multi-steps reactions. Probability of the thiol⇔thione tautomerism reaction occurrence via single-proton intramigration for N–H to nearby C[dbnd]S was DFT-theoretically monitored. The thione tautomer isomer structure formation was supported by X-ray single crystal measurement, the lowest energy DFT-optimized structures of the molecule in gas-phase reconcile with the thionic tautomer structure solved by X-ray technique. Several physico-chemically tools like CHN-elemental analyses, FT-IR, MS, TG/DTG, XRD, UV–Vis.,1H and 13C NMR were served for the compound characterization. Experimental methods X-ray diffraction, NMR, UV–Vis. and FT-IR spectroscopy and their corresponding quantum-parameters were computed for their electronic and structural output. The computed Hirshfeld surface analysis (HSA) and molecular electrostatic potential (MEP) reflected the presence of several H-bonds and C–H…π (C[dbnd]C) as short contacts which was detected experimentally by XRD-packing analysis.