Site-selective spectroscopy of Eu-doped orthorhombic lanthanum and monoclinic yttrium polyphosphates

In order to study the influence in the change of the coordination environment of the cationic sites on the luminescent properties of rare-earth ions doping polyphosphates Ln(PO₃)₃ (Ln = La, Y) with two different structures, the time-resolved luminescence of the Eu³⁺ ion, used as structural probe, is reported. La(PO₃)₃ has an orthorhombic structure in which only one position with eight coordination is available for the cation, while Y(PO₃)₃ adopts the Yb(PO₃)₃ structure in which four slightly different octahedral sites are available for the trivalent rare-earth ion. Site-selective excitation of the ⁵D₀ level was performed and luminescence decay times of each Eu³⁺ site were measured at 77 K. The spectroscopic results are discussed and correlated with the structural data.     

Synthesis of Long Afterglow SrAl2O4 :Eu2+, Dy3+ Phosphor by Microemulsion Method

Long afterglow SrAl2 O4: Eu2 , Dy3 phosphor was synthesized by microemulsion method. The synthesized phosphor was characterized by XRD. XRD pattern indicates that the phosphor has monoclinic SrAl2 O4 crystal structre.The microstructure of the phosphor was investigated by SEM and TEM. The excitation spectrum, emission spectrum and afterglow decay curve were measured, the wide range of excitation wavelength indicated that the luminescent material could be excited by the light from ultraviolet ray to visible light, and the emission maximum was found to peak mainly at λem of 525 nm. The sample excited by ultraviolet visible light could emit bright green light.     

TTA-NA-Phen-Eu离子型配合物的合成及表征

以噻吩甲酰三氟丙酮(HTTA)、3-羟基2-萘甲酸(H2NA)和邻菲咯啉(Phen)为配体,合成了Na2[Eu(TTA)(NA)2(Phen)]新的离子型配合物,并用元素分析、红外光谱、紫外光谱对它进行了表征。     

以不同键合方式合成的Eu-AA-MMA共聚物的表征及荧光性质

用两种不同的键合方式，即先聚合再络合(先合成丙烯酸一甲基丙烯酸甲酯共聚物，再将铕离子(Eu^3 )引入此共聚物)和先络合再聚合(先合成丙烯酸铕，再合成丙烯酸铕一甲基丙烯酸甲酯共聚物)的方式将稀土元素Eu引入到高分子基体中。采用红外光谱、X射线衍射和DSC等手段对其结构、物相和热性能进行表征，确定铕与高分子基质发生配住。荧光光谱表明得到的配位聚合物是一种良好的光致发光材料，在紫外光下发出高亮度、单色性的特征红光。     

铕、铽依诺沙星配合物的合成和光谱特性

合成了Eu3+、T b3+与依诺沙星配合物,并用元素分析法和ICP-AES法确定了配合物的组成为RE(enx)3C l3.8H2O。红外光谱表明,依诺沙星配体以羧酸根同中心离子发生螯合。紫外光谱表明,配合物的紫外吸收波长较配体稍有红移,且强度明显增强。荧光光谱表明,Eu3+配合物在592nm和612nm处出现Eu3+的特征荧光峰,分别对应5D0-7F1和5D0-7F2的能级跃迁。T b3+配合物在490nm和545nm出现T b3+的特征发射峰,且545nm处发射峰强度最大,二者分别对应5D4-7F6和5D4—7F5跃迁。     

Crystal Structure and Luminescence Spectra of Novel Coordination Layer of {[Eu(m-BDC)(NO3)(Phen)(H2O)]2·2CH3CH2OH}n

The crystal structure of a novel Eu3 coordination polymer, {[Eu(m-BDC)(NO3)(Phen)(H2O)]2 · 2CH3CH2OH}n (m-BDC=1,3-benzenedicarboxylate, Phen=1, 10-phenanthroline), was obtained and its high-resolution luminescence spectra at 77K were measured. The μ2-carboxylate of m-BDC constructs the binuclear building block in which each Eu3 ion is coordinated by four oxygen atoms of m-BDC anions, one oxygen atom from water molecule, two oxygen atoms of nitrate and two nitrogen atoms of Phen, respectively. The μ1-carboxylate of m-BDC conjugates the binuclear units one-dimensional chain or a ribbon, while the hydrogen bonds between ribbons assemble the structure two-dimensional layer with a thickness equaling to the width of the ribbon. The luminescence spectra reveal that the two Eu3 ion sites in the binuclear building blocks have slight environmental difference. The C1 local symmetry of Eu3 ion is concluded from both crystal structure measurement and luminescence spectra.     

Electrochemical Behaviour of Europium-Ferrocene Derivative Complex Chemi cally Modified Electrodes

Electrochemical behaviours of Europium-ferrocenederivative complex chemicallymodified electrodes were studied inthe paper. Various factors whichaffect the voltammetry of the thinfilm modified electrodes, and thecharge transport process of the thinfilm electrode were discussed. Sizeof the hydrated anion (counterion), concentration of the electrolyte, swelling property of thefilm in the solvent and thickness ofthe film have significant effects onthe voltammetry of the thin filmelectrode. Electro…     

Syntheses and fluorescent properties of complexes of Eu(Ⅲ) with HTTA,TPPO and benzoic acid

A series of Eu(Ⅲ) complexes of α-thenoyltrifluoroacetone(HTTA) with trioctylphosphine oxide(TPPO) and benzoic acid(BA) or its two derivatives, p-toluic acid(PTA) and p-methoxybenzoic acid(POA) were synthesized and were characterized with elemental analysis, IR spectroscopy, scanning electronic microscopy and fluorescent spectra. The complexes were revealed to be Eu(BA)(TTA)2TPPO2, Eu(PTA)(TTA)2TPPO2 and Eu(POA)(TTA)2TPPO2. The excitation and absorption spectra of the complex Eu(POA)(TTA)2TPPO2 in MeOH solution were investigated in detail. The experimental result showed that relatively cheap materials with sharp red luminescence could be pre-pared, when benzoic acid or its two derivatives were added in Eu(Ⅲ) complexes of α-thenoyltdfluoroacetone with trioctylphosphine oxide. The relative fluorescence intensity of the Eu(Ⅲ) complexes decreased in the following order: Eu(POA)(TTA)2TPPO2> Eu(PTA)(TTA)2TPPO2>Eu(BA)(TTA)2TPPO2.     

PMA—Eu^3＋—TPPO等三元配合物的合成与发光性质研究

合成了PMA-Eu与TPPO（Phen、Bipy)形成的系列固体配合物,分析了它们的组成,常温下研究了它们的荧光光谱。发现TPPO（Phen、Bipy)作第二配体加入到Eu^3 的配合物中,能使Eu^3 的红色荧光大大增强,其中TPPO比Phen、Bipy对Eu^3 具有更好的荧光增强效果。     

离子液体中Ln(Ⅲ)/TBP的配位反应研究

应用吸收光谱和荧光光谱法研究了在水饱和的1-丁基-3-甲基咪唑双(三氟甲基磺酰亚胺)盐(C4mimTf2N)中Ln(Ⅲ)(Ln=Nd、Eu)与磷酸三丁酯(TBP)的配位反应。结果表明:温度分别为10、25、40、55、70℃时,Nd(TBP)3+的稳定常数lgβ分别为0.68±0.03、0.76±0.02、0.89±0.03、0.97±0.03、1.04±0.03,lnβ对100/T在10~70℃范围内表现出良好的线性关系,配位反应的焓变在该温度范围内基本保持不变,由范特霍夫方程计算得到的Ln(Ⅲ)与TBP配位反应的焓变为11.52kJ/mol;25℃下,Eu(TBP)3+的稳定常数lgβ为0.78±0.06,略大于Nd(TBP)3+的配位稳定常数,与镧系收缩效应一致。