Crystal structure, MEP/DFT/XRD, thione ⇔ thiol tautomerization, thermal, docking, and optical/TD-DFT studies of (E)-methyl 2-(1-phenylethylidene)-hydrazinecarbodithioate ligand

Abstract

As small-molecule (E)-methyl 2-(1-phenylethylidene)hydrazinecarbodithioate has been prepared and characterized by X-ray single-crystal analysis. In order to elucidate the nature of the intermolecular interactions in the structural lattice, the Hirshfeld surface analysis (HSA) calculation was correlated to the XRD-packing result. Moreover, the XRD bond lengths and angles were compared to their DFT/B3LYP/6-311G(d,p) relative parameters. Considering the thione isomer as a kineticly favoured isomer, the single proton intra-migration from H-N to form S-H thionethiol tautomerization process was successfully computed via QST2 model. Additionally, Mulliken Atomic Charge (MAC), Natural Population Analysis (NPA), and Molecular Electrostatic Potential (MEP) analyses were carried out to confirm this process. The electron transfer and optical behavior of the ligand in DMSO have been exanimated with TD-DFT and HOMO/LUMO calculations. The thermal behavior of the compound was determined in an open room condition via TG/DTG. The two identified isomers of (E)-methyl 2-(1-phenylethylidene)-hydrazinecarbodithioate (thione and thiol forms) were docked against TcAChE (PDB:1EVE) revealed, conspicuous, different protein–drug structures, however, reflects identical docking scores (−7.2 Kcal/mol each), which is compared to the standard donepezil drug used in this study.