Syntheses, characterization and X-ray crystal structures of Co(III) and Mn(II) complexes of pyrimidine derived Schiff base ligands

Enthused research on DNA-binding and DNA-cleavage aptitude of mixed ligand metal complexes

Five new Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) mixed ligand complexes have been synthesized using a Schiff base precursor (obtained by the condensation of N-(4-aminophenyl)acetamide and 4-chlorobenzaldehyde) as main ligand and 1,10-phenanthroline as co-ligand. They have been characterized by microanalytical data, IR, UV-Vis, magnetic moment values, conductivity and electrochemical measurements. The spectral data reveal that all the complexes exhibit octahedral geometry. The high electrical conductance of the complexes supports their electrolytic nature. The monomeric nature of the complexes has been assessed from their magnetic susceptibility values. These complexes are better antimicrobial active agents than the free ligands. DNA (CT) binding properties of these complexes have been explored by UV-Vis., viscosity measurements, cyclic voltammetry, and differential pulse voltammetry measurements. The oxidative cleavage activity of the complexes has been studied using supercoiled pUC19 DNA by gel electrophoresis. The experimental results show that the complexes are good intercalators.

{2,2'-[(2,2-Dimethyl-propane-1,3-di-yl)bis-(nitrilo-methyl-idyne)]diphenolato}palladium(II) ethanol hemisolvate

The asymmetric unit of the title complex, [Pd(C₁₉H₂₀N₂O₂)]·0.5C₂H₅OH, contains two mol­ecules of a Pd^II complex of a Schiff base ligand with an N₂O₂ donor set and one ethanol mol­ecule. The Pd^II centers are in distorted square-planar geometries with the N₂O₂ donor atoms of the tetra­dentate Schiff base dianions. The ethanol mol­ecule takes part in an O—H⋯O hydrogen bond. In the crystal structure, mol­ecules are stacked approximately along the b-axis direction. The O atom and three H atoms of the solvent molecule are disordered over two positions; the site occupancy factors are ca 0.8 and 0.2.