Synthesis, characterization and antibacterial activity of new sulfonamide derivatives and their nickel(II), cobalt(II) complexes

Methanesulfonicacid hydrazide (a sulfonamide compound, msh: CH3SO2NHNH2) derivatives: methylsalicylaldehydemethanesulfonylhydrazone (5msalmsh), 5-methyl-2-hydroxyaceto-phenonemethanesulfonylhydrazone (5mafmsh) and their Ni(II), Co(II) complexes have been synthesized for the first time. The structure of these sulfonamide compounds has been investigated by using elemental analyses; FT-IR, 1H NMR, 13C NMR, LC–MS, and UV–Vis spectrometric methods; magnetic susceptibility; conductivity measurements; thermal studies. The crystal structure of 5msalmsh has been investigated by X-ray analysis. The antibacterial activities of synthesized compounds were studied against gram positive bacteria: Staphylococcus aureus, Bacillus subtilis, and Bacillus magaterium; and gram negative bacteria: Salmonella enteritidis, and Escherichia coli by using the microdilution broth method. The biological activity screening showed that ligands have more activity than complexes against the tested bacteria.

Graphical abstractThe structure of 5-methylsalicylaldehydemethanesulfonylhydrazone (5msalmsh) was determined by X-ray crystal diffraction studies.The structural characterizations of the sulfonamide complexes were made by using the elemental analyses, spectroscopic methods, magnetic and conductance studies, and thermal analysis. From the spectroscopic characterizations, it is concluded that sulfonylhydrazones act as bidentate ligands, coordinating through >CN and phenolic –OH via deprotonation.Figure optionsDownload full-size imageDownload as PowerPoint slide