New thioether-hydrazide based ONS donor Schiff base and its Pd(II) complex: Synthesis, crystal structure, thermal analysis, hirshfeld surface analysis, quantum chemical studies and molecular docking

Abstract

A new acyclic arylthioether-hydrazide Schiff's base – N′-(2-(methylthio)benzylidene)-3-phenylpropanehydrazide, LH and its palladium(II) complex, [PdLCl] have been synthesized and characterized by elemental analysis, FT-IR, 1H NMR and 13C NMR and single crystal X-ray diffraction. The ligand is coordinated to the central Pd(II) ion through (O−,N,S) donor type with distorted square planar geometry. The torsional angle between arylthioether (Ar-S-C) to hydrazide nitrogen around CN is 179.27(18)° reveal the trans arrangement of the groups in LH. The stability of [PdLCl] was determined by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The Hirshfeld surface analysis and fingerprint plots revealed the various intermolecular interactions. The DFT calculations were performed to outline the optimized structure, frontier molecular orbitals, reactive parameters, and molecular electrostatic potential. Further the intramolecular interactions were analysed using of DFT and QTAIM calculations. The topology analysis revealed the shifting of the electron density towards the metal and the strained metal coordination sphere. The effective binding interaction of LH and [PdLCl] are studied against Mycobacterium tuberculosis DNA gyrase.