Exploring molecular structure, spectral features, electronic properties and molecular docking of a novel biologically active heterocyclic compound 4-phenylthiosemicarbazide

Abstract The experimental and theoretical studies on the structure and vibrations of 4-phenyl thiosemicarbazide (PTSC) (IUPAC: 3-amino-1-phenylthiourea) have been carried out using FT–IR, FT-Raman, FT–NMR, UV-Vis spectrum and quantum chemical density functional theory (DFT) method. The DFT optimization of the title molecule was carried out using B3LYP with 6-311++G(d,p) basis set. Conformational and tautomeric stability of PTSC was investigated. Molecular electrostatic potential (MEP) map of PTSC was calculated to identify the reactive sites. The lower HOMO-LUMO energy gap indicates that the title compound is most reactive and least stable which supports the biological activity. The NMR chemical shifts indicated that the observed values not only depend on the structure of the molecule being studied, but also on the solvents used. Thermodynamic properties were also studied for PTSC and temperature dependence of molecular properties was also examined. Molecular docking studies shows that the favourable ligand protein interactions present in the title molecule and confirms biological activity of PTSC.