Papers by Keyword: Rare Earth Complex

Abstract: Working with acylaminocarboxylate ligands, we used ethanol and water as a solvent, and the europium complexes were prepared using a chemical reaction method in solution. The elements were analyzed and characterized by polarizing microscope and XRD, respectively. The surfaces of complexes in the solid state were observed by polarizing microscope morphology. XRD diffraction data confirms the periodic long range order/disorder structure of these europium complexes. We also found that diversified material was easily formed by the rare earth complexes. Using the above tests, the structural information of the Eu complexes in the glassy state, liquid crystal glassy state and crystalline states was obtained

Abstract: This paper discusses the structure design, light conversion agents, vehicles, colorants and the selection of other functional additives of light conversion advanced invisible falsification- resistant ink, the preparation of the light conversion falsification-resistant ink and rare earth metal europium complex, and analyzes rare earth metal europium complex, Eu(C5H7O2)3C12H8N2, through infrared spectrometer, element analyzer and fluorescence spectrometer. The results of the above analysis identify the composition of rare earth metal europium complex, its excitation spectrum ranging from 200nm to 400nm, and its emission spectrum ranging from 580nm to 640nm. Experiments suggest when the mixture of rare earth metal europium complex and white ink with titanium dioxide in a fixed proportion is printed on any objects, it appears reddish orange light under ultraviolet irradiation, which achieves the advanced invisible anti-counterfeiting effect.

Abstract: In this paper, the solid-state reactions between EuCl₃ and pyridine dicarboxylic acid (DPA) are studied. The complex is synthesized by one step solid state reaction at room temperature and the material was characterized by element analysis, fourier transform infrared (FTIR) spectra, absorption and fluorescence spectra. The compositions of complex has been confirmed to be [Eu (DPA)₂(Cl)₂]•6H₂O. Organic light emitting diodes based on the structure of ITO/PEDOT:PSS/PVK:PSS/PVK:Eu/Bphen (12 nm)/LiF(1 nm)/Al were fabricated, the electroluminescence of Eu³⁺ complex was investigated under different driving voltage.

Abstract: Quaternary europium complex EuxGd_(1-x)(POA)(TTA)₂Phen were synthesized by doping no-fluorescent inert ions Gd³⁺ with ligands of POA, α-thenoyltrifluoroacetone (TTA), and o-phenanthroline(Phen).IR spectra was studied , indicate that these complexes have similar structures, have bonded with the ligands.The fluorescent properties,the influence of fluorescent property by doping ions Gd³⁺ were studied. The results showed that the doping ions Gd³⁺ can enhance the fluorescence intensities, the best mole ratio of europium to gadolinium is 6：4.

Abstract: A β-diketonate-type ligand, N-(3-methoxyl–phenyl)ketoacetamide (L), and its complexes with europium (III) and terbium (III) were synthesized. The ligand and complexes were characterized by elemental analysis, IR spectra, ¹HNMR spectra, mass spectra and luminescent spectra. The complexes were characterized by elemental analysis, IR spectra. The stoichiometry of metal-to-ligand in the complexes also was confirmed by the fluorescence behavior of the ligand and complexes in CH₃CH₂OH solution. In addition, the fluorescence properties of complexes in DMF, CH₃OH, CH₃CH₂OH, acetone and CHCl₃ were investigated. The characteristic fluorescence of terbium (III) was assigned.

Abstract: A binary and ternary rare earth complexes were synthesized. The structure and composition of the complexes were characterized by FT-IR and Elemental Analyzer. It is found that the complexes have excellent fluorescence intensity and thermal stability. Photoluminescent measurements show that Phenanthroline (Phen) could efficiently transfer energy to Eu³⁺ and sensitize the luminescence of Eu³⁺. The copolymers of complexes, methyl methacrylate (MMA) and methacrylic acid (HMA) emit characteristic fluorescence of Eu³⁺. The fluorescence intensity enhanced with the complexes content increasing. But the apparent copolymers of Eu(AA)₃ have stronger luminous intensity than that of Eu(AA)₃Phen under limit solubility because Phen reduces the content of solvable Eu³⁺ in the mixture of MMA and HMA.

Abstract: Ribbon-like microfibers of a new composite of europium complex Eu(aspirin)₃(Phen) (aspirin is acetylsalicylic acid; Phen represents 1,10-phenanthroline) and polystyrene (PS) were prepared successfully by electrospinning with different mass ratios of Eu(aspirin)₃(Phen) complex to PS = 1:10, 1:40 and 1:160. The microfibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and fluorescence spectrophotometry. It was found that the fibers displayed excellent photoluminescence properties compared with rare-earth complex. The photoluminescence intensity and the emission intensity of the peak at 616 nm (⁵D₀→⁷F₂) of Eu-ions increased with the Eu(aspirin)₃(Phen) loading. No obvious fluorescence quenching was observed. Further discussion on the structural and optical properties of the microribbons was presented. This kind of materials might be expected to be applied for optical or optoelectronic devices.

Abstract: The reaction of 2-acetyl-2'-chloroacetanilide (L) with rare earth nitrates in CH₃CH₂OH followed by recrystallization in CH₃CH₂OH gave rise to colorless block crystals materials. The complexes and ligand were analyzed by FAB, elemental analysis(C, H, N), FT-IR spectra, TG-DTA, molar conductivity and X-ray single crystal diffraction. The fluorescence properties of ligand and the Eu (Ⅲ) complex also have been investigated. The results of crystal structure and spectral data show that the rare earth ions coordinated with oxygen and nitrogen atoms of the ligand, the nitrate and coordinated water molecules. The Eu (Ⅲ) complex material shows characteristic red emissions.

Abstract: Fluorescence falsification-resistant ink is one of the most widely used ink in packaging and printing industry. In this paper, europium complexes were synthesized by doping no-fluorescence inert ions Gd3+. IR spectra indicated that these complexes have similar structures, have bonded with the legends. The fluorescence properties indicated that the doping ions Gd3+ can enhance the fluorescence intensities, the best mole ratio of Gd3+ to Eu3+ is 1:9；At last, fluorescence falsification-resistant ink was prepared, the fluorescence ink showed the characteristic emission of Eu3+ , showed invisible in visible light and showed red fluorescence under ultraviolet light.

Abstract: Rare earth complex Eu(phen)2Cl3·2H2O synthesized by precipitation method was incorporated into MCM-41 mesoporous molecular sieves which were synthesized via a hydrothermal method. Hybrid inorganic/organic mesoporous luminescent material Eu(phen)2/MCM-41 has been characterized by XRD, TEM, IR, UV-visible spectra and fluorescence spectra. Results indicated that the hybrid mesoporous material has typical structure of MCM-41 and retains the same pore structure as MCM-41 after the assembly process. The fluorescence spectra of these materials present a series of narrow lines assigned to 5D0 → 7F0,1,2,3,4 transitions. The high emission intensity observed is a promising property for application of the rare earth complex in technological luminescent devices.