Synthesis, structural characterization and biological activities of transition metal complexes derived from 2,4-dihydroxybenzaldehyde n(4)-methyl(phenyl)thiosemicarbazone

•A new thiosemicarbazone, (E)−2-(2,4-dihydroxybenzylidene)-N-methyl-N-phenylhydrazinecarbothioamide (L)was synthesized. Single crystals were grown by slow evaporation of its ethanolic solution at room temperature. The grown crystals were characterized by SCXRD, elemental analyses, FT-IR, 1H NMR and UV–Vis spectral analyses.•The Co(II), Ni(II) and Cu(II) complexes of 2,4-dihydroxybenzaldehyde N(4)-methyl(phenyl)thiosemicarbazone were synthesized and characterized by elemental analyses, FT-IR, 1H NMR, UV–Vis, EPR spectral analyses and conductance- and magnetic moment measurements.•All the compounds were tested for inhibition activity against P.aeruginosa, E.coli, S.aureus, B.subtilis, A.niger and C.albicans.•The free-radical-scavenging ability of the ligand and metal complexes were evaluated by DPPH method. A new thiosemicarbazone, (E)-2-(2,4-dihydroxybenzylidene)-N-methyl-N-phenylhydrazinecarbothioamide (L) was synthesized. Single crystals were grown by slow evaporation of its ethanolic solution at room temperature. The grown crystals were characterized by SCXRD, elemental analyses, FT-IR, 1H NMR and UV-Vis spectral analyses. Complexes of L with Co(II), Ni(II) and Cu(II) chlorides were synthesized and their structures were elucidated by elemental analyses, FT-IR, 1H NMR, UV-Vis, EPR spectral analyses and magnetic moment measurements. All these compounds were tested against microbial strains. The free-radical-scavenging ability of the ligand and the metal complexes was measured by their interaction with the stable DPPH free radical and all the compounds showed appreciable antioxidant activity. [Display omitted]