Lanthanum(III) Complexes with N-alk(en)yl-1,10-phenanthroline-2-methyleneamine and their DNA-binding Mode

Abstract

Five new tridentate ligands and their corresponding La(III) complexes, [La(III)(L) 2 (H 2 O) n ](ClO 4 ) 3 where n = 2,3 and 4; L is N-methyl-1,10-phenanthroline-2-methyleneamine (L 1 ), N-ethyl-1,10-phenanthroline-2-methyleneamine (L 2 ), N-propyl-1,10-phenanthroline-2-methyleneamine (L 3 ), N-n-butyl-1,10-Phenanthroline-2-methyleneamine (L 4 ), and N-benzyl-1,10-phenanthroline-2-methyleneamine (L 5 ), have been synthesized, and characterized by elemental analysis, IR, far-IR, 1 H-NMR, thermal gravity analysis and conductance measurement. The interaction of the lanthanum(III) complexes with calf thymus DNA was studied by means of UV, fluorescence, CD and viscosity measurements. Using ethidium bromide as a fluorescence probe, the binding mode of the complexes with calf thymus DNA was studied spectroscopically. All the results suggest that the complexes perhaps interact with calf thymus DNA by intercalative and coordination binding mode.