Synthesis, Characterization and Antibacterial Activity of New Ln(Ⅲ) Complex with Unsymmetrical Schiff Base Ligand

A new unsymmetrical Schiff base ligand （H2LLi） was synthesized using L-lysine, o-vanillin and salicylaladyde. Three solid metal complexes of this ligand [Ln（H2L）（NO3）] NO3·2H2O （Ln=Sm, Ho, Tm） were prepared and characterized by elemental analyses, IR spectra, UV spectra, TG-DTG and molar conductance. The ligand synthesized are chelating agent. The nitrogen atoms of Schiff base, oxygen atoms of hydroxybenzene, methoxide and carboxyl are all coordinated to the metal ions. Carboxyl and the nitrate ion within the coordination sphere are coordinated to the metal ion in a mondentate or bidentate fashion. Water molecules are lied in crystal substances. The antibacterial activity of the ligand and its complexes was also studied. The antibacterial experiments indicate that they have antibacterial activity to E. coli, S. aureus, B. subtilis and the complexes have higher activity than the ligand.