Novel thiosemicarbazone complexes as anticancer agents: Synthesis, characterization, cytotoxicity, docking, and density functional theory studies

New Co (II), Ni (II), and Cu (II) complexes based on ρ‐dimethylaminobenzaldehyde thiosemicarbazone ( DABT ) as chelating agents were synthesized. The structure of the three complexes was determined by elemental analysis and TGA with IR, UV–Vis, XRD, ESR spectra, conductivity, and magnetic measurements. It was found that the isolated DABT complexes have tetrahedral structure with a neutral nature. The antitumor activity of DABT complexes using viability assay was examined against hepatocellular carcinoma cell lines (HepG‐2). The DABT complexes have moderate activity with respect to the standard drugs. DABT– Ni (II) complex has higher antitumor activity (IC 50 = 12 μM) than the other DABT complexes. In addition, a molecular docking study was performed for DABT and its complexes to investigate their therapeutic features as topoisomerase inhibitors. It is clear that the most effective compound was DABT– Ni (II) complex to bind to 3QX3. Also, density functional theory calculations with the structure–activity relationship were computed for DABT and its complexes using the Gaussian program. There was confirmation between the obtained theoretical data and the experimental studies.