2,4-Dihydroxy-5-[(5-mercapto-1H-1,2,4-triazole-3-yl)diazenyl] benzaldehyde acetato, chloro and nitrato Cu(II) complexes: Synthesis, structural characterization, DNA binding and anticancer and antimicrobial activity

Acetato, chloro and nitrato Cu(II) complexes of a novel azo compound, namely 2,4-dihydroxy-5-[(5-mercapto-1H-1,2,4-triazole-3-yl)diazenyl]benzaldehyde, have been prepared. The stoichiometry, stereochemistry and bonding fashion of these copper chelates were deduced via elemental analyses, spectral methods and conductivity and magnetic measurements. Infrared spectral data confirmed the participation of azo N atom and the deprotonated OH group. UV-visible spectral data and magnetic measurements indicated octahedral stereostructure for the acetato and nitrato compounds and square planer for the chloro compound. Thermogravimetric analysis was applied to investigate the thermal degradation of the metal chelates. The thermo-kinetic parameters were computed. The molecular modeling technique was used to support the predicted geometry of the prepared chelates. The interaction between the Cu(II) complexes and calf thymus DNA was studied using two techniques: absorption and viscosity measurements. The values of binding constant obtained from the absorption spectral method were calculated and found to be 4.23 x 10(4), 26.93 x 10(4), 13.01 x 10(4) and 5.36 x 10(4) M-1 for ligand and acetato, chloro and nitrato complexes, respectively. The antimicrobial activities were evaluated against various bacterial and fungi strains. The in vitro antitumor efficacy of the synthesized compounds was investigated against the HEPG2 cell line.