Preparation,Characterization And Fluorescence Properties Of Eu Organic Three Element Complex

Rare earth elements have excellent physical and chemical properties, especially have excellent optical, electromagnetic and catalytic properties. They have been widely applied in various fields of national economy and modern science technology. As a new type of functional materials, the rare earth luminescent materials have been widely used in the fields of the lighting, display, bio imaging and security because of the unique luminescence properties(such as narrow band emission light, long service life, large displacement Stokes and so on) of the rare earth ions. In this thesis, in order to study the influence of second ligand on the fluorescence properties of rare earth complexes of three organic luminescence of rare earth with europium(Eu), the red light emitting organic rare earth three element complex was prepared by choosing ?-diketone(?-thiophene three fluoride acetone, TTA) as the first ligand, 1,10- phenanthroline(Phen) and its derivatives as the second ligand. The effects of second ligand 1,10-phenanthroline(Phen) and its derivatives as ligands on the luminescence of rare earth organic complexes were discussed.(1) The six rare earth organic complexes were successfully synthesized by choosing the synthesis of three complexes the TTA as the first ligand, 1,10-phenanthroline, 2- bromo- phenanthroline, 3,8- dibromo- phenanthroline, 4,7- dibromo- phenanthroline, 4,7- diphenyl- phenanthroline and 4,7- dimethyl- phenanthroline as the second ligand containing rare earth europium. The six rare earth organic complexes were characterized by element analysis and infrared spectrum analysis.(2) By thermogravimetric analysis, the results indicated that the decomposition temperature of six rare earth organic complexes are more than 300?, being good thermal stability. The six rare earth europium complexes of thermogravimetric curves were similar, suggesting that when the first ligand was the same, the boiling point of the first ligand was less than the second ligand because the thermal decomposition temperature of the first ligand was associated with its physical properties and the formation of new rare earth coordination bond, but had no influence on the second ligand.(3) The excitation spectra, emission spectra, fluorescence lifetime and quantum efficiency of six rare earth organic complexes were measured by steady-state transient fluorescence spectrometer. The excitation spectra showed that the second ligand 1,10-phenanthroline on single electron withdrawing substituent, the optimum excitation wavelength unchanged. The second ligand 1,10-phenanthroline was provided with a plurality of electron withdrawing substituent, the optimum excitation wavelength was slightly longer, but rare earth europium complexes of the general rules of the excitation intensity was weakened. The second ligand 1,10-phenanthroline was electron donating substituent, the optimum excitation wavelength become shorter, but the excitation intensity is weaker than the second 1,10-phenanthroline. The results of emission spectra showed that the second ligand 1,10-phenanthroline on electron and electron donating groups did not affect the characteristic fluorescence of rare earth europium complexes from europium ion, but it had an effect on its strength. The general rule of fluorescence lifetime and quantum efficiency of the electron withdrawing substituent has shortened and weaken against it, when the 1,10-phenanthroline derivative substituents on the as the electron donating, excitation intensity and emission intensity of europium complexes are strengthened, fluorescence lifetime growth, quantum efficiency increased obviously.