Abstract
The designed target compound ofN-acetyl indole linked to a fused triazolo/thiadiazole scaffold was synthesized via the reaction of 4-amino-5-(1H-indol-2-yl)-1,2,4-triazol-3(2H)-thione as the starting material with acetic anhydride under reflux conditions for 6 h, resulting in an excellent and pure chemical yield. The structural features of the designed compound were confirmed using spectroscopic tools including single crystal X-ray diffraction analysis along with(1)H-NMR,C-13-NMR, 2D-NMR, and high resolution mass spectrometry. Using Hirshfeld analysis, we determined the molecular packing depends on strong interactions (O center dot center dot center dot H and N center dot center dot center dot H) along with weak interactions (S center dot center dot center dot H, C center dot center dot center dot H and H center dot center dot center dot H). The shortest contacts corresponding to the N3 center dot center dot center dot H12 (2.490 angstrom), N2 center dot center dot center dot H5 (2.503 angstrom), and O1 center dot center dot center dot H2 (2.490 angstrom) interactions were confirmed based on the Hirshfeld analysis. The calculated dipole moment was 6.6557 Debye. The atomic charge distribution, molecular electrostatic potential map, and reactivity descriptors are also discussed. The computed NMR spectra of the requisite compound correlated well with the results obtained experimentally. The UV-Vis electronic spectra of the requisite compound were simulated using the TD-DFT method and compared with the experimental data. The different sigma ->sigma*, pi ->pi*, n ->sigma*, and n ->pi* donor-acceptor interactions and their interaction energies stabilized the studied system to 9.84, 20.65, 29.33, and 45.82 kcal/mol, respectively.