Bio-active mixed ligand Cu(II) and Zn(II) complexes of pyrimidine derivative Schiff base: DFT calculation, antimicrobial, antioxidant, DNA binding, anticancer and molecular docking studies.

A new series of bio active Cu(II) and Zn(II) complexes CuL(phen) (), ZnL(phen) (), CuL(bpy) (), ZnL(bpy) () have been synthesized using the pyrimidine derivative Schiff base () [ = 2-(4,6-dimethylpyrimidin-2-ylimino)methyl)-4-nitrophenol], 1,10-phenanthroline (phen), 2,2'-bipyridine (bpy) and acetate salts of Cu(II) and Zn(II). UV-Visible, FT-IR, H-NMR, ESR, elemental analysis, molar conductance and EI-MS spectral techniques have been used to endorse the square planar geometry for the complexes -. The optimized molecular structure and the harmonic vibrational frequencies have been scrutinized by DFT methods. The antibacterial and antifungal activity of Schiff base () and complexes - indicates that complex acts as good antimicrobial agent against microbial strains than , complexes - and standard drugs streptomycin and nystatin. DNA cleavage study of the complexes - exposes that complexes and spectacle good cleaving agent than complexes and . The interaction of complexes - with CT DNA using absorption, emission and viscometric measurements signifies that complexes - bind an intercalation mode. The highest binding constants () for the complex is confirmed as 7.83 × 10 M and 2.98 × 10 M by absorption and emission spectrum respectively. These experimental observations were found to be close to the theoretical observations investigated by the molecular docking technique. Antioxidant property of the complexes - using DPPH assay clinches that complex produces significant scavenging effect than other compounds. The result of cytotoxicity of the Schiff base () and complexes - shows that complex shows better ability to inhibit the growth of cancer cells. Communicated by Ramaswamy H. Sarma.