Synthesis, characterization, XRD, SEM, DNA binding, and effect of γ‐irradiation of some new Ni (II) and Co (II) complexes with thiosemicarbazone ligand: In vitro antimicrobial and antioxidant activities.

Ni (II) and Co (II) complexes of thiosemicarbazide ligand (2‐(anilinoacetyl)‐N‐(3‐methylphenyl)hydrazine‐1‐carbothioamide(H2LB) have been prepared and characterized by 1HNMR, IR, elemental analyses, molar conductance, UV–visible spectra, magnetic susceptibility measurements, thermogravimetric analysis (TGA/DTG), and X‐ray differaction pattern before and after irradiation. The results confirmed that gamma rays enhanced the stability of irradiated compounds compared with those non‐irradiated. Density functional theory (DFT) calculations of synthesized compounds were completely optimized with respect to the energy using B3LYP level. DNA binding of compounds before and after gamma irradiation has been studied. Inhibitory effect on the growth of bacteria against gram‐positive (Streptococcus pyogenes) and gram‐negative (Escherichia coli) of synthesized compounds have been investigated. The results revealed that Ni (II) complex after gamma irradiation showed a higher antibacterial activity against gram positive and gram negative bacteria more than all investigated compounds. The ability of scavenging 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radical by our synthesized compounds was investigated on the basis of the determination of IC50 values. [ABSTRACT FROM AUTHOR]