New nickel(II), palladium(II), platinum(II) complexes with aromatic methanesulfonylhydrazone based ligands. Synthesis, spectroscopic characterization and in vitro antibacterial evaluation

Methanesulfonicacid hydrazide (a sulfonamide compound, msh: CH3SO2NHNH2) derivatives: salicylaldehydemethanesulfonylhydrazone (salmsh), 2-hydroxyacetophenonemethanesulfonyl hydrazone (afmsh), 2-hydroxy-3-metoxybenzaldehydemethanesulfonylhydrazone (o-vanmsh) and their Ni(II), Pd(II) and Pt (II) complexes have been synthesized. The structure of these compounds has been investigated by using elemental analyses; FT-IR, 1H- NMR, LC-–MS, UV–Visible spectrometric methods; magnetic susceptibility; conductivity measurements; thermal studies. The antibacterial activities of synthesized compounds have been determined in vitro against gram positive bacteria; Staphylococcus aureus ATCC 25923, Bacillus cereus RSKK 709, and gram negative bacteria; Pseudomonos aeruginosa ATCC 27853, Escherichia coli ATCC 35268 by paper disc diffusion and microdilution broth methods. The biological activity screening showed that metal complexes have more activity than their ligands against the tested bacteria.

Graphical abstractStructures of aromatic methanesulfonylhydrazone complexes. Percentage of inhibition of ligands and metal (II) complexes.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► New sulfonylhydrazone complexes were synthesized and characterized. ► Antibacterial activities of the compounds against four bacteria were determined. ► Percentage of inhibition for Pd(o-vanmsh)2 shows excellent activity.