Three salicylaldehyde derivative Schiff base Zn complexes:synthesis,DNA binding and hydroxyl radical scavenging capacity

摘要

Three new Schiff base ligands N-(3-formyl-5-methylsalicylidene)-2-aminoethanol (H2L~1),N-(3-hydroxylmethyl-5-methylsalicylidene)-2-aminoethanol (H_3L~2),2,6-bis(o-carboxyphenyliminomethene)-4-methylphenol (H3L3) and their binuclear Zn~(II) complexes [Zn_2HL~1)Cl_2,o 2H2O (ZnHL~1),[Zn2(H2L2)2]Cl2 o H2O (ZnH2L2) and [Zn2(HL3)Cl2] o H2O (ZnHL3) were synthesized and characterized by ~1H-NMR,elemental analysis,IR and molar conductivity.The results suggest,in every case,two Zn~(2+) ions were bridged by phenolic OH group oxygen,forming a binuclear complex.The binding properties of these complexes to calf thymus DNA (ct-DNA) were investigated.Absorption and fluorescence spectra are together suggestive that both ZnHL~1 and ZnHL~3 interact with ct-DNA through intercalative mode,while ZnH2L2 interact with ct-DNA by non-intercalative interaction.Moreover,ZnHL3 can bind to ct-DNA more strongly than ZnHL1.These complexes also exhibited good scavenging activity on the hydroxyl radical (·OH),which are better than those of their corresponding ligands.