Synthesis, structural characterization, Hirshfeld analyses, and biological activity studies of Ni(II) and Zn(II) complexes containing the sulfonohydrazone group

Abstract

In this work, the nickel ([NiL2]) and zinc ([ZnL2]) complex structures of N'-(dipyridin-2-ylmethylene)-4-methylbenzenesulfonohydrazide [LH] have been synthesized. The structures of the complexes have been investigated by using X-ray single crystal, elemental analysis, FTIR, and UV–Vis spectrophotometric methods. The two compounds crystallize isotypic in monoclinic space group P21/c. From elemental analysis data, the stoichiometry of the complexes was found to be 1:2 (metal/ligand). IR spectra indicate that the ligand behaves as tridentate with an NNO donor sequence in its enolate form. The coordination of the metal atoms takes place through the pyridine nitrogen, imine nitrogen, and sulfonyl oxygen atoms. Thermal analysis of [NiL2] and [ZnL2] complexes were performed and the thermoanalytical curves obtained. Hirshfeld surfaces of [NiL2] and [ZnL2] complexes were investigated and the interaction energies between the molecules participating in CH…π interactions in the complex [NiL2] were calculated by using the CE-HF energy model, and the energy values were found to be −76.27 and −57.08 kJ mol−1, respectively. Additionally, the ligand and the complexes were examined for their antimicrobial activity against pathogenic microorganisms by the well-diffusion method. These compounds were exhibited the varying degree of inhibitory effects on the growth of different tested pathogenic strains.