Synthesis, X-ray, spectroscopic characterization (NMR, FT-IR, Raman, and UV–VIS), Hirshfeld surface analysis, DFT, molecular docking, and estimating anticancer of 5,6-diphenyl-3-(prop-2-yn-1-ylthio)-1,2,4-triazine

A new 1,2,4-triazine derivative, 5,6-diphenyl-3-(prop-2-yn-1-ylthio)-1,2,4-triazine (4) has been synthesized through the condensation of 5,6-diphenyl-1,2,4-triazine-3-thiol with propargyl bromide in acetone solution in the presence of triethylamine at room temperature for one hour. Its chemical structure was elucidated from spectral data (¹H NMR, ¹³C NMR, FT-IR, FT-Raman, UV/Vis, and mass spectrometry) and confirmed by a single crystal X-ray diffraction analysis. Geometrical optimization of the molecular structure was performed at the B3LYP/6–311++G(d,p) level of theory. The intercontacts between different units in the crystal of 4 were explored by a Hirshfeld surface analysis (HSA), which reveals that H^…H contact has the highest contribution of intermolecular contacts. The anticancer activity of 4 was explored by estimating its binding affinity into the binding site of human DNA topoisomerase as the molecular target of various anticancer compounds using molecular docking. This study indicated 4 to fit well into the DNA topoisomerase binding site and to form a stable complex with its amino acids. The ADMET properties reveal that 4 obeys Lipinski's rule of five, has high gastrointestinal (GI) absorption, and may exhibit penetration through the Blood-Brain Barrier (BBB).