A Series Of Novel Zinc-Rare Earth Metals Complexes Constracted By2-Substituted-8-Hydroxyquinoline Ligand:Syntheses, Structures And Photoluminiescence

The organic ligand with8-hydroxyquinoline has the feature widely high luminous efficiency and brightness, good film-forming, high glass transition temperature, the characteristics of a simple synthetic process and so on, which has applies widely on OLED. Since C.W.Tang first reported that8-hydroxyquinoline aluminum was used to make the green organic light-emitting diodes(OLED).8-Hydroxyquinoline has been the ideal organic light-emitting materials more than a decade in the history of the development. The researches about8-hydroxyquinoline aluminum,8-hydroxyquinoline lithium,8-hydroxyquinoline zinc and many other organic small molecule material have done. The research of8-hydroxyquinoline aluminum has matured and successfully applied to commercial production.Reference domestic and foreign literature in combination with other8-hydroxy quinoline synthesis ligands, we choose a large conjugated substituents on2-hydroxyquinolineto alter the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO), which change the emission wavelength of complexes.8-Hydroxyquinoline complexes with itself low luminous efficiency of rare earth ion coordination, rare-earth metal ions disturb the organic ligand or ligand-to-metal charge transfer. Two kinds of new (E)-2-[2-(4-benzoate)ethenyl]-8-hydroxyquinoline and (E)-2-[2-(4-benzoic acid)ethenyl]- 8-hydroxyquinoline ligands equipped with a double-ended with double-digit base metals complexes. Synthesis of the rigidity of molecular complexes, has a planar structure, molecular deformation is difficult, the probability of occurrence of non-radiative transitions to the ground state is greatly reduced, since the extent of the complex conjugate is increased,π-π*electronic transitions more prone. In this paper,(E)-2-[2-(4-benzoate)ethenyl]-8-hydroxyquinoline and (E)-2-[2-(4-benzoicacid) ethenyl]-8-hydroxyquinoline ligands were synthesized using2-methyl-8-hydroxyquinoline and thirteen types of complexes were synthesized using two ligands.Their structures were characterized and measured their fluorescence properties and fluorescence lifetime. Its main contents and conclusions of the study were as follows:1. Two types of8-hydroxyquinoline ligands were synthesized using2-methyl-8-hydroxyquinoline with formylbenzoate. Two ligands were characterized by1H NMR and IR spectra. The crystal structures of ligands were determined by single crystal X-ray diffraction method. Eight types of complexes were synthesized using (E)-2-[2-(4-benzoate)ethenyl]-8-hydroxyquinoline with rare earth nitrates. Other five types of complexes were synthesized using (E)-2-[2-(4-benzoic acid)ethenyl]-8-hydroxyquinoline with zinc acetate and rare earth nitrates. Their structures were characterized by elemental analysis, molar conductance, IR spectra.2.8-Hydroxyquinoline derivative is a good light-emitting materials, their luminescence properties were studied, fluorescence spectra were measured at200nm-800nm wavelength.(E)-2-[2-(4-benzoate)ethenyl]-8-hydroxyquinoline lanched yellow light at580nm, after adding the rare earth ions, ligands by the rare-earth ions in the center of the perturbation and light, luminous intensity is greatly enhanced.(E)-2-[2-(4-benzoic acid)ethenyl]-8-hydroxyquinolinelanched red light at620nm, the metal ions Zn2+was added after the emission intensity is enhanced, adding rare earth metal, stronger luminous intensity, luminous perturbation mechanism is also metal ions disturb the organic ligand. Fluorescence lifetime is about104ns, the fluorescence lifetime compared with the compounds of similar properties in the same order of magnitude, they are excellent fluorescent material.