Synthesis, characterization and DNA studies of transition metal(II) complexes of Schiff base derived from p-aminoacetanilide and salicylaldehyde

A new tridentate Schiff base ligand (HL) was prepared by the condensation of salicylaldehyde and p-aminoacetanilide and characterized by microanalytical data, IR, UV-Vis, H-1 NMR and mass spectra. Complexes with Cu-II, Co-II, Ni-II and Zn-II were synthesized and characterized by spectral and analytical techniques. The data show that the complexes have composition ML2 where M = Cu-II, Co-II, Ni-II and Zn-II. The Schiff base acts as a tridentate mono basic donor, coordinating through the deprotonated phenolic oxygen, carbonyl oxygen and azomethine nitrogen atoms. The UV-Vis spectral data suggest that the complexes have distorted octahedral geometry. Their low electrical conductance values reveal that these chelates are non-electrolytes. Their magnetic susceptibility values provide evidence for the monomeric nature. The electrochemical experiments neatly demonstrate that the present ligand system can stabilize the higher oxidation states of metal ions. The nuclease activity of the above metal complexes shows that the complexes cleave DNA through redox chemistry. In the presence of H2O2, all the complexes are capable of cleaving Lambda DNA.