Photolysis of light-transforming polymer material

Light-transforming polymer materials activated with the compositions on the basis of the europium carboxylates with different ligands and anthranilic acid exhibiting the intense luminescence in the spectral range 400–700 nm are prepared. It is shown that light stability of polymer materials on the basis of the aboveprepared compositions is higher than of polymer materials activated with the europium salts. The photolysis of luminescent polymers was studied. For the compositions EuL₃C₁₃H₁₃N₃·xH₂O + anthranilic acid gradual increase in the luminescence intensity of the europium ion is marked.     

The luminescent properties of polyethylene films with admixtures of luminophores based on europium compounds

Polyethylene films activated with europium(III) complexes with carboxylic acids and Eu(L)₃ · nD · xH₂O + ANT compositions, where L is the trifluoroacetic, toluyl, or cinnamic acid anion and ANT is anthranilic acid, were prepared. The intensity of luminescence of the polymeric compositions depended on the content of luminophores (molar ratio between europium compounds and anthranilic acid). An analysis of the excitation spectra showed that, in polymer—Eu(L)₃ · nPhen · xH₂O + ANT compositions, there was effective energy transfer from phenanthroline to anthranilic acid levels.     

Luminescent and photochemical properties of the lanthanide-containing polymer materials

The light-transforming polymer materials have been obtained based on the mixed europium cinnamates, cinnamic acid, and high density polyethylene. The materials exhibit an intensive luminescence in the range of 400–700 nm. The photostability of the materials has been higher than that of polymer materials activated solely with europium compounds. The photolysis of the luminescent polymers has been studied. For the obtained polymer compositions the build-up of europium ion and cinnamic acid luminescence has been observed.     

脂肪酸铕配合物掺杂聚乙烯、聚丙烯和聚苯乙烯光致发光复合材料

合成了正己酸铕、正辛酸铕、月桂酸铕和硬脂酸铕4种不同碳链链长的脂肪酸铕配合物,通过哈克转矩流变仪将铕配合物(质量分数1%)机械掺杂于3种不同透明度的聚乙烯(PE)、聚丙烯(PP)和聚苯乙烯(PS)通用树脂中,制备了系列铕配合物掺杂聚合物光致发光复合材料,考察了配体、配合物、聚合物基体对复合材料的外观、透明性及其荧光性能的影响。 结果表明,4种脂肪酸铕配合物及其掺杂的复合材料在紫外光的激发下均在593、617 nm处发射强的Eu3+离子5D0→7F1、5D0→7F2跃迁的特征荧光;脂肪酸配体的碳链长短对铕配合物及复合材料的发光影响较小;PE、PP复合材料发光颜色与红光铕配合物相同,PS复合材料因基体PS和Eu3+离子的发光共同作用而呈现了玫瑰红的荧光发射。     

Photochemical behavior of luminescent compositions based on antimony(III) and europium(III) complexes in high-pressure polyethylene

Luminescent and photochemical properties of polymer compositions based on the Eu(NO₃)₃(Phen)₂ complex and complexes of antimony(III) halides with diphenylguanidine are investigated. It is found that high-pressure polyethylene (HPPE) containing europium(III) and antimony(III) complexes in combination exhibits efficient transfer of electronic excitation energy from antimony(III) levels to europium(III) levels and photosensitization of europium(III) luminescence. It is shown that the europium(III) and antimony(III) complexes increase the stability of HPPE to UV radiation.     

The luminescent properties of divalent europium complexes of crown ethers and cryptands

The luminescent properties of divalent europium complexes with crown ether, azacrown ether, N-pivot-azacrown ether, and cryptand in methanol or water have been systematically investigated under UV irradiation. These divalent europium complexes show greatly enhanced emission from 417 nm to 488 nm in the visible blue region in comparison with that of the methanol solution of EuCl₂. The aqueous solution of EuCl₂ is non-luminescent. This obvious distinction in luminescent properties between the macrocyclic ligand-coordinated divalent europium and uncoordinated divalent europium is attributed to the “insulation effect” of Eu²⁺ ion from the solvent molecules of CH₃OH and H₂O by the macrocyclic crown ether or cryptand encapsulation to divalent europium. Moreover, these macrocyclic ligands provide an additional restriction to the electronic charge expansion of the excited Eu²⁺. This also contributes to the enhancement of the Eu²⁺ luminescence. Among all the investigated macrocyclic ligands, 15-crown-5 (15C5) affords the largest enhancement to the Eu²⁺ emission. The intensity of the Eu²⁺–15C5 complex is 690 times that of the EuCl₂ methanol solution with the same Eu²⁺ concentration. This special emission enhancement effect is related to the particular complex composition of 1:3 (Eu²⁺:15C5) and corresponding configuration of Eu²⁺–15C5 complex in methanol. Concerning the mechanism, the luminescence enhancement of divalent europium by complexation with these macrocyclic crown ether or cryptand ligands is found to be initiated from the decrease in non-radiative rate constant rather than from the increase in radiative one.

The divalent europium complexes of methacrylate polymeric polyether derivatives such as 15C5-, 18-crown-6- (18C6), and cryptand [2.2.1]- or [2.2.2]-containing polymer and copolymer have also been prepared. Their luminescent properties in solid state have been studied to aim for practical application. As a similar situation to the simple polyether complexes, the divalent europium complex with 15C5-containing polymer or copolymer shows the largest luminescent enhancement effect. Its emission intensity reaches about 20% that of the commercial inorganic luminescence product CaWO₄:Pb (NBS 1026). In addition, the doping effect of several divalent ions, namely Mg, Sr, Ba and Zn in polymeric complexes, has also been investigated according to the luminescence concentration quenching mechanism in solid state luminescence materials. The emission intensity of 15C5-containing polymer europium(II) complex is raised to twice stronger by doping of Zn²⁺ ion.     

EXAFS, SAXS and Eu3+ Luminescence Spectroscopy of Sol-Gel Derived Siloxane-Polyethyleneoxide Hybrids

Hybrid Eu³⁺-doped silica-poliethyleneoxide (PEO) nanocomposites with covalent bonds between the inorganic (siloxane) and organic (PEO) phases have been obtained by sol-gel process. These materials are transparent, flexible and present high Eu³⁺ luminescence output. Their luminescence properties, local environment around europium ions and structure have been investigated as a function of europium content. EXAFS measurements indicate that the increase in Eu-doping induces a decrease in Eu³⁺ coordination number. An increase in symmetry degree around the metal ion is also observed for increasing Eu³⁺ concentration, while non radiative decay paths from the ⁵D₀ excited state become more important. SAXS results suggest the preferential interaction of europium ions with ether-type oxygens of the polymer chains. However, the existence of interactions between the cations and the carbonyl groups from urea bridges located at the siloxane-PEO interface can not be excluded.     

Synthesis and luminescence of zinc and europium alpha-thiophene carboxylate polymer

The zinc and europium alpha-thiophene carboxylate polymer with very strong red luminescence was prepared by rheological phase reaction method from zinc acetate, europium oxide and alpha-thiophenecarboxylic acid. Molecular weight, thermal analyses and X-ray diffraction pattern were measured. 1H NMR, 13C NMR, IR, XPS, UV, excitation and emission spectra were studied. The polymer with amorphous structure and 7.565x10(5) g/mol weight-average molecular exhibited excellent solubility in common organic solvents and better thermal stability under 270 degrees C in air. The quantum yield of the polymer in acetone was 0.6 relative to quinoline in 0.05 mol/l H(2)SO(4) solution. The energy of the pi,pi(*) excited state of C(4)H(3)SCO(2)(-) can be transferred to Eu(3+) ion resulting in emission from the 5D(0)-->(7)F(j) of Eu(3+) ion through the polymeric chains. Zn(2+) can effectively enhance the luminescence of Eu(3+) in alpha-thiophenecarboxylate polymer.     

Assembly, characterization, and photoluminescence of hybrids containing europium(III) complexes covalently bonded to inorganic Si-O networks/organic polymers by modified beta-diketone

1-(2-naphthoyl)-3,3,3-trifluoroacetonate (NTA) was grafted to the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TEPIC) and used as the first kind of precursor, and other kinds of precursors (PVPD, PMAA, and PVPDMAA) were synthesized through the addition polymerization reactions of the monomer 4-vinylpyridine and methacrylic acid. Then, these precursors coordinated to rare earth ions, and the three kinds of hybrid polymeric materials were obtained after hydrolysis and copolycondensation with the tetraethoxysilane (TEOS) via a sol-gel process. FTIR, ultraviolet, ultraviolet-visible diffuse reflection and photoluminescent spectra, electronic microscopy diagraphs, room-temperature X-ray diffraction patterns, and TG plots were characterized, and the results reveal that the hybrid materials imbedded into the single polymer (PVPD and PMAA) showed more uniformity in the microstructure, more efficient intramolecular energy transfer between europium ions and the modified ligand NTA-Si and more excellent characteristic emission of europium ions under UV irradiation with higher (5)D(0) luminescence quantum efficiency and longer lifetime than the hybrid materials imbedded into the multipolymer (PVPDMAA).     

Luminescence studies on europium-strontium phthalate system

New lanthanide luminescence materials were prepared. The main component lanthanide chelates generally need a relatively high content of rare earth. Inorganic luminescence materials only need low rare earth concentration using doped method. Similarly, lanthanide chelates can be added to complex matrix by doped method. In this way, low rare earth concentration emission was successful in the lanthanide chelates system as well. The influence of europium ion concentration on luminescence intensities was discussed. When the europium ion weight in the complex is only about 0.6%, the sample exhibits good luminescence properties. The fluorescence, Fourier transform infrared spectra, micro-Raman and electron spin resonance spectra of the samples were measured. And a possible luminescence mechanism was suggested by the inorganic doped mechanism and the luminescence of lanthanide complexes together.     

Influence of the Nature of Carboxylic Acid on the Luminescence and Spectral Properties of (Carboxylato)bis(dibenzoylmethanato)europium(III) Complexes

A series of (carboxylato)bis(dibenzoylmethanato)europium(III) complexes containing anions of both saturated and unsaturated carboxylic acids were synthesized to compare the luminescence and spectral properties of heteroligand Eu(III) complexes. (Carboxylato)bis(dibenzoylmethanato)europium(III) complexes with unsaturated acid anions were synthesized for the first time. The compounds obtained were characterized using elemental analysis and luminescence and IR spectroscopy. These studies revealed two types of influence of the nature of an acid substituent on the luminescence spectra of (carboxylato)bis(dibenzoylmethanato)europium(III) complexes. The anomalous Stark structure of the luminescence spectra of one group of compounds is attributed to the charge transfer state at 77 K.     

新型β-二酮铕配合物的合成和性能研究

以肉桂酸和苯乙酮为原料合成了1,5-二苯基-4-烯-1,3-戊二酮（DPPD）配体,以DPPD为第一配体,1,10-邻菲罗啉为第二配体,合成了稀土铕配合物并通过红外光谱进行了表征,同时,研究了配合物的发光性能。     

Preparation and Luminescence Properties of the Ternary Europium Complex Incorporated into an Inorganic/Polymer Matrix by a Sol-Gel Method

Ternary europium complexes with thenoyltrifluoroacetone (TTA) and phenanthroline (phen) were incorporated into SiO₂/polymer matrix by a sol-gel method. The gels exhibit the characteristic emission bands of europium ion. In addition, Eu³⁺ presents a longer fluorescence lifetime in gel than in the corresponding pure complex powder. Concentration effects on the luminescence intensity were investigated. The reasons that are responsible for above results are also discussed in the context.     

Synthesis and photophysical properties of silica nanoparticles based on europium(iii) complexes

Monodisperse 280?C480 nm silica particles doped with europium complexes with thenoyltrifluoroacetylacetone and adducts with some phosphine oxides as luminophores were prepared for the first time by the optimized Stober procedure using surfactants. The size and the polydispersity of the obtained particles depend on the luminophore incorporated in the polymer template. The photophysical properties of aqueous dispersions of the europium(iii)-doped silica particles were studied by the luminescence method.     

New polymeric based materials: terpoly(aniline,diphenyl amine,and o‐anthranilic acid) / kaolinite composites

Terpolymers of aniline, diphenyl amine and o‐anthranilic acid (PANIDPAA) / kaolinite clay composites were synthesized by 1:1:1 molar ratios of the respective monomers with different percentages of kaolinite clay particles via in situ chemical terpolymerization. The spectral characteristics upon incorporation of o‐anthranilic acid and diphenyl amine units into the polyaniline backbone in presence of kaolinite clay were investigated. The results were justified by measuring the UV–Vis absorption spectra, FT‐IR for PANIDPAA emeraldine base (EB), and PANIDPAA EB / kaolinite clay composite. Also, the thermal gravimetric analyses for the isolated terpolymer powder in the bulk in absence and in presence of kaolinite clay were carried out. Moreover, the morphology of the polymer clay composites system was studied by the scanning electron microscope micrographs at different magnifications. X‐ray diffraction was used to measure the nature of polymer and extent of crystallinity present in the neat terpolymer and terpolymer / kaolinite composite materials. Copyright © 2016 John Wiley & Sons, Ltd.     

Highly sensitive sorption-luminescence determination of trace europium with preconcentration on silica chemically modified with iminodiacetic acid

Features of a sorption-luminescence method for the determination of trace europium were studied. The method includes the preliminary sorption of europium at pH 7.1 from solutions with silica chemically modified with iminodiacetic acid, the subsequent treatment of the sorbent with 2-thenoyltrifluoroacetone at pH 8.0, and the measurement of the intensity of luminescence of the surface three-component europium complex at 613 nm. The effect of moisture as the quencher of luminescence of the surface europium complex was studied, and techniques for its removal were proposed. Sorption in the static mode provides the detection limit of europium of 7 × 10⁻⁵ μg/mL. The calibration plot is linear in the range of two orders of magnitude of europium concentration in solutions. The relative standard deviation in the determination of 1.5 × 10⁻² μg/mL europium is 5%. In the dynamic mode of sorption from 1000 mL of an analyzed solution with the use of sorption-desorption, the detection limit of europium of 8 × 10⁻⁷ μg/mL was attained. Original Russian Text ? R.D. Voronina, N.B. Zorov, 2007, published in Zhurnal Analiticheskoi Khimii, 2007, Vol. 62, No. 3, pp. 230–237.     

Regulation of excitation and luminescence efficiencies of europium and terbium benzoates and 8-oxyquinolinates by modification of ligands

The opportunities of optimisation of luminance of the lanthanide compounds by modification of ligands are discussed. Variations of the excitation and luminescence efficiencies at introduction of nitro- (NO₂), sulfo- (SO₃⁻), hydroxy- (OH), amino- (NH₂), and phenylamino- (NHC₆H₅) groups in the aromatic ligands were studied. Investigation of luminescence and luminescence excitation spectra of europium and terbium compounds with 10 derivatives of benzoic acid, 2-furancarboxylic acid and their adducts with 1,10-phenanthroline and 2,2′-bipyridine was undertaken. Study of the spectra of lanthanide 8-oxyquinolinates was carried out also. Luminescence efficiencies were measured at 77 and 300 K. Paths of the energy transfer from the ligands to Ln³⁺ ion were examined. Influence of radicals on the energies of the ligand triplet states and on the energies of the ligand–metal charge transfer states (LM CTS) of europium compounds was analysed. High luminescence efficiencies of europium and terbium benzoates, and terbium anthranylates and salicylates were obtained. Effect of increasing the luminescence efficiencies of europium salicylates and 8-oxyquinolinates at introduction of acceptor nitro-and sulfo-groups in the ligand was revealed. Channel of dissipation of the excitation energy through the ligand π^*–n transition of europium and terbium nitro- and dinitrobenzoates was found. Influence of relative positions of the lowest triplet levels of two non-equivalent ligands of compound on the energy transfer to Eu³⁺ and Tb³⁺ ions was considered.     

稀土铕、铽配合物在温度发光传感领域的研究进展

稀土发光配合物材料基于其独特的4f-4f电子跃迁表现出优异的发光性能,特别是铕和铽配合物材料,发光波长在可见光区范围内,发射谱带狭窄且尖锐(半峰宽通常小于10 nm),非常适合应用于显示设备和传感装置.同时,具备温度依赖发光性能的铕和铽配合物能够实现高灵敏度、高效的温度传感过程,使其有望用于流体动力学、航空航天、环境工...     

Morphological structure and dispersity of luminescent heteroligand europium cinnamates

The luminescence characteristics of heteroligand europium cinnamates are reported. As follows from the IR spectra, cinnamic acid coordinates with europium in these compounds in the bidentate fashion. The shape, size, and surface morphology of particles of heteroligand europium cinnamates were determined by scanning electron and atomic force microscopy. Heteroligand europium complexes usually form plate-like and needle-like microcrystals of size 0.1–15 μm.     

Effect of Aliphatic Chain Length in the Ligand on Photophysical Properties and Thin Films Morphology of the Europium Complexes

Chelating ligands based on polydentate diamides of 2,2'-bipyridyl-6,6'-dicarboxylic acid with a high affinity for lanthanide ions have been synthesized. The effect of the size of lipophilic aliphatic substituents in the ligand on the photophysical characteristics of europium complexes in acetonitrile solutions and in the solid state, as well as on the morphology of thin films obtained by the spin-coating method, was studied. The external and internal luminescence quantum yields have been measured, the luminescence lifetimes at 300 and 77 K were determined, and the sensitization efficiency values for europium complexes were calculated. The phosphorescence of gadolinium(III) complexes was used to determine the energy difference between the triplet level of the ligand and the resonance level of europium.