Synthesis, characterization, DNA binding, protein binding, antioxidant and anti microbial activity of tetrazole ring based complexes

•Cobalt and copper complexes of 2-(1H-Tetrazol-5-yl) acetohydrazide were synthesized by Microwave method and characterized. They were identified with octahedral and tetrahedral geometries, respectively.•CT-DNA binding studies were performed using UV–vis, fluorescence and viscometry.•BSA binding studies were performed using UV–vis and Fluorescence. In both binding studies and antimicrobial studies Co complex exhibited highest propensity.•Antioxidant studies were performed using UV–vis. The ligand and its complexes exhibited mild radical scavenging activity compared to Ascorbic acid. Novel Cu(II) and Co(II) complexes of 2-(1H-Tetrazol-5-yl) acetohydrazide were synthesized by microwave assisted green synthesis. These compounds were characterized by electronic, FT-IR, 1H NMR, Mass, thermogravimetric, PXRD, ESR, SEM and EDAX techniques. The analytical data show that for Cu(II) complex, metal to ligand ratio is 1:1 and for Co(II) complex, metal to ligand ratio is 1:2. Electronic spectra predicts the tetrahedral geometry for the Cu(II) complex and octahedral geometry for the Co(II) complex. ESR showed superhyperfine spectrum suggesting covalent character in Cu complex. gII = 2.4097 is consistent with dxy ground state supporting its tetrahedral geometry. The interaction of the ligand and complexes with Calf Thymus DNA (CT-DNA) was explored by using absorption, fluorescence spectroscopic, viscometry methods and molecular docking. Interaction of the ligand and complexes with Bovine Serum Albumin (BSA) protein was investigated by absorption and fluorescence techniques. Co (II) complex exhibited highest DNA & BSA binding propensity. Investigation of the antioxidative properties showed that the metal complexes have mild radical scavenging potency against DPPH radical. Ligand and its two complexes were tested for antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. Both complexes showed good bactericidal activity against Staphylococcus aureus, the Co(II) complex was found to be more potent than Streptomycin. [Display omitted]