Syntheses and Biological Activities of Lanthanide Metal Complexes with Nitronly Nitroxide

Using compounds ErCl3 center dot 6H(2)O (1), TbCl3 center dot 6H(2)O (2), DyCl3 center dot 6H(2)O (3), GdCl3 6H2O (4), and radical NITPh-p-Cl (5) (2-(4'-chlorphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), four complexes based on lanthanide ions and nitronyl nitroxide radical, Ln(hfac)(3)(NITPh-p-Cl)(2) (Ln = Er (6), Tb (7), Dy (8), Gd (9), hfac = hexafluoroacetylacetonate) have been synthesized and characterized by elemental analysis, IR, and UV-vis methods. The filter paper scraps diffusion method was used to determine the antibacterial performance with four lanthanide ions, radical and four lanthanide-radical complexes. The results reveal that antibacterial activities of the four complexes are stronger than that of the accordance pure lanthanide ions for the testing bacterium. The antibacterial activity of the complex 9 is best in all the compounds.