New The Polyamine Polycarboxyl Pyridine Ligand And Its Eu (iii) And Tb (iii) Complexes, Synthesis And Fluorescence Properties,

The carboxylate ligands have a strong ability of chelation to rare earth ions and good sensitivity to the luminescence of Eu(III) and Tb(Ⅲ) ions. Especially, the lanthanide aroma carboxylate complexes possess more stabile and abundant structures, due to their larger conjugation and planarity and various chelation manners. Consequently, it is to confirm the structure and investigate their luminescence properties to provide theories for their applications that are the study emphasis of the lanthanide aromatic carboxylate complexes.In this paper, the concepts of luminescence, variety of ligands and applications of lanthanide carboxylate complexes were introduced. Three novel ligands were designed and synthesized: 2,4,6-tri(N,N-dicarboxyletheyl-aminoethyl)-pyridine (L1), N,N,N1,N1-(2,6-bis((3-(aminoethyl)-5-methyl-1H-pyrazol-1-yl)methyl)py ridine)hexakis (L2),2,6-di((3-(N,N-dicarboxyletheyl-aminoethyl)-5-methyl-pyrazol-1-yl)methyl)pyridine (L3), six Eu(Ⅲ) and Tb(Ⅲ) complexes were prepared, and the structure of intermediates, ligands and complexes were characterized by the infrared spectra, elemental analysis and proton nuclear magnetic resonance in detail. Meanwhile, the optimal conditions of bromination of 2,4,6-tri(hydroxylmethyl)pyridine were obtained.In addition, the luminescenct properties of ligands and complexes were investigated, the results indicated that the rare earth ions could be sensitived by the three ligands, especially, the ligand L3 could transit energy to the center-metal ions more efficiently and let its corresponding complexes only present strong and narrow characteristic metal-centered luminescence, the luminescence intensity were closed to 10000.