Synthesis and characterization of zinc(II) complexes with new pyridine-based ligands: crystal structure, Hirshfeld surface analysis, and molecular docking study of lung cancer cell

The new ligands 2-chloro-6-{2-[(2,4,6-trimethylphenyl)methylidene]hydrazinyl}pyridine and 2-chloro-6-{2-[1-(4-nitrophenyl)ethylidene]hydrazinyl}pyridine and their Zn(II) complexes were synthesized and characterized by elemental analysis, LC/MS-MS, thermal analysis, UV-vis spectroscopy, molar conductivity, H-1 NMR, C-13 NMR, FT-IR, X-ray diffraction, as well as single-crystal X-ray crystallography. Hirshfeld surface analysis with 2-D fingerprint plots was carried out to estimate intermolecular interactions in the crystal and molecular electrostatic potential (MEP) diagrams of ligands were mapped by using Hartree-Fock theory STO-3G base set of Hirshfeld surface. Additionally, it is suggested that both Zn(II) complexes have a distorted octahedral geometry as a result of spectroscopic and analytical data. For 1, two HL1 ligands act as tridentate while in 2, Zn is coordinated with aromatic pyridine nitrogen, imine nitrogen of two bidentate HL2 ligands, one nitrate group and one oxygen atom from the aqua ligand. The molecular docking studies of the synthesized compounds were carried out. The complexes showed better binding affinity compared to the ligands and hydrophobic interactions of the compounds against targeted protein residues played an important role. Remarkably, it can be suggested that 1 is a very suitable drug candidate for lung cancer.