Solid-State Synthesis, Characterization, Biological Studies and Theoretical Evaluation of (E)-2-(2-(naphthalene-2-yloxy)-1-phenylethylidene) Hydrazine Thiocarboxamide

Abstract

The title compound (E)-2-(2-(naphthalene-2-yloxy)-1-phenylethylidene) hydrazine thiocarboxamide (NAPTCAR) is synthesized by condensing 2-(Naphthalen-2-yloxy)-1-phenyl-ethanone (2-NAPETH) with thiosemicarbazide in 1: 1 molar ratio in solid state medium. Purity of compounds has been confirmed by Thin Layer Chromatography. Characterization and structure elucidation of these ligands have been made using 1H NMR, 13C NMR and FTIR spectral studies and DFT calculations. Interestingly, 13C NMR spectrum of thiosemicarbazone ligand exhibits the presence of two conformational structures. The HOMO – LUMO energy gap of conformer A is found to be almost equal to that of conformer B. Conformer A is has relatively a stronger nucleophilic character than conformer B as indicated by the molecular electrostatic potential surface. Van der Waals and the steric interactions play a dominant role in stabilizing the structure of both the conformers. The ligands have been examined for antibacterial and antifungal activities and are quite active in this respect.