Ligand-sensitized fluorescence of Tb3+ in Tb3+-dibutylphosphate complexes: application for the estimation of DBP

The fluorescence of Tb(3+) is sensitized by complexation with dibutylphosphate (DBP) and tri-n-butylphosphate (TBP). The excitation maximum for the Tb(3+)-DBP complex occurs at 218.5 nm, while that for the Tb(3+)-TBP complex is observed at 228.0 nm. Both complexes yield Tb(3+) fluorescence at 548 nm. The difference in the excitation maxima for the two complexes has been used to advantage for the estimation of DBP in the presence of TBP. DBP is the main degradation product of TBP in the PUREX process and the method described in this work can thus serve as a useful analytical tool in monitoring the quality of the TBP in the process. This method has been shown to be applicable for the estimation of DBP when present to an extent of 0.1-10% of TBP, in TBP/dodecane solutions.     

Eu~(3+)和Tb~(3+)冠醚配合物的合成、荧光性质及与DNA作用研究

合成了含联萘骨架的酰胺型开链冠醚配体及稀土苦味酸盐配合物RE(pic)3L[L=N,N-乙基,苯基-N’,N’-二苯基-1,1’-联萘-2,2’-二(氧杂乙酰胺),RE=Eu3+,Tb3+],通过元素分析、IR、TG-DTA和摩尔电导率对配合物进行组成和结构推测。荧光光谱表明:Eu3+配合物的荧光强度远大于Tb3+配合物,说明配体L的三重态能级与Eu3+的激发态能级匹配较好。通过光谱法和粘度法研究了配合物与DNA的作用方式为插入作用,求出了Eu3+,Tb3+配合物与DNA的结合常数分别为4.072×104L.mol-1,8.780×103L.mol-1,证明配合物与DNA的作用大小是Eu3+(pic)3LTb3+(pic)3L.     

Synthesis, crystal structure, and magnetic studies of one-dimensional cyano-bridged Ln3+-Cr3+ complexes with bpy as a blocking ligand

The reaction of Ln(NO3)3.aq with K3[Cr(CN)6] and 2,2'-bipyridine (bpy) in a water/ethanol solution led to two families of complexes: 4 one-dimensional (1D) complexes of the formula trans-[Cr(CN)4(mu-CN)2Ln(H2O)3(bpy)2]n.4nH2O.3.5nbpy (Ln3+ = La, Ce, Pr, and Nd) and 10 1D complexes of the formula trans-[Cr(CN)4(mu-CN)2Ln(H2O)4(bpy)]n.3.5nH2O.1.5nbpy (Ln3+ = Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu). The structures for the fourteen complexes [LaCr]n (1), [CeCr]n (2), [PrCr]n (3), [NdCr]n (4), [NdCr]n (4'), [SmCr]n (5), [EuCr]n (6), [TbCr]n (7), [DyCr]n (8), [HoCr]n (9), [ErCr]n (10), [TmCr]n (11), [YbCr]n (12), and [LuCr]n (13) have been solved. Complexes 1-4 crystallize in the orthorhombic space group Pbam and are isomorphous; complexes 4'-13 crystallize in the triclinic space group PI and are isomorphous. The X-ray structural characterization of complexes 1-4 shows the presence of a discrete decameric water cluster built around a cyclic hexameric core stabilized by the solid-state structure, which represents another new mode of association of water molecules. The Ln3+-Cr3+ magnetic interaction is negligible in 6 and 12, antiferromagnetic in 2, 4', 7, 8, 9, 10, and 11, and unresolved for 3. The complex 5 is a ferrimagnet because its magnetic studies suggest the onset of a very weak ferromagnetic three-dimensional ordering.     

铽含量对硫氧化钇纳米发光材料荧光性能的影响

用燃烧法制备了不同Tb3+掺杂量的Y2O2S:Tb3+纳米发光材料,同时用高温固相法制备了不同Tb3+掺杂量的Y2O2S:Tb3+体相材料,X射线晶体衍射结果表明,制备的纳米材料和体相材料均为单一的Y2O2S相.由Debye-Scherre公式估算得到纳米颗粒的平均粒径大约为10 nm.讨论了纳米材料和体相材料Y2O2S:Tb3+中Tb3+的掺杂浓度对荧光性能的影响.激发光谱表明纳米材料的基质吸收带与体相材料相比向高能端移动了6nm,应用久保理论对此进行了定性的解释.     

稀土离子Tb~(3+)对卵清蛋白稳定性的影响

在室温、p H=7.4、10 mmol/L 4-羟乙基哌嗪乙磺酸(Hepes)缓冲溶液条件下,利用荧光光谱研究了卵清蛋白(Ova)与Tb~(3+)的结合性质.利用荧光探针2-对甲苯胺基-6-萘磺酸钠(TNS)检测了Tb~(3+)对Ova疏水区的影响.通过化学变性实验分析了Ca2+和Tb~(3+)对Ova结构稳定性的影响.结果表明,Ova可以与Tb~(3+)形成1∶2的复合物,Tb~(3+)的结合使其疏水区暴露程度增加,TNS的荧光增强.Ova的解折叠曲线呈现三态的变化(N■■I■■U).Ca2+可以增加I■■U过程的稳定性,Tb~(3+)对N■■I和I■■U两个解折叠过程都有影响.     

Effect of OH- on the luminescent efficiency and lifetime of Tb3+-doped yttrium orthophosphate synthesized by solution precipitation

In this work, we use the solution precipitation method to synthesize Tb3+-doped yttrium orthophosphate, which is a green-emission luminescent material. The evolution of hydrated yttrium orthophosphate (YPO4.2H2O) to dehydrated yttrium orthophosphate (YPO4) is observed in the heat-treatment process, simultaneously, accompanying the structural transformation from monoclinic churchite-type to tetragonal xenotime-type structure. Furthermore, the luminescent efficiency of Tb3+-doped YPO4 presents a sharp jump at a critical temperature in this heat-treatment process. Interestingly, this critical temperature is close to the structural transformation temperature. The remarkable change of luminescent efficiency seems to be related to the structural transformation. However, the FTIR and fluorescent decay measurements at 10 and 300 K indicate that the OH group is the origin of luminescent efficiency change. OH- ions with high vibration frequency provide an efficient means to quench the luminescence. The comparison of the luminescent efficiency, OH- content, and lifetime of 5D4 of Tb3+ between two samples with the same crystal structure proves that the structural transformation has no significant effect on the luminescent efficiency and lifetime. On the basis of these results, it is proposed that correctly preventing OH- ions inside the host matrix or effectively eliminating them may improve the luminescent efficiency greatly. This idea also may be applied to other optical systems.     

Laser spectroscopic studies of Tb3+-doped oxyfluoroborate glass

Tb3+-doped oxyfluoroborate glasses have been prepared for different concentrations of Tb. The absorption, fluorescence and photoacoustic spectra of these have been recorded and studied. It is marked that the fluorescence intensity of different fluorescence transitions decreases with the increase of Tb ion concentration in the glass. This quenching at higher concentration is due to the energy transfer among the excited and nearest neighbor unexcited Tb ions in the glass. The lifetime measurement confirms it, as the lifetime of a particular state was found to decrease with the increase of Tb ion concentration in the glass. The mechanism of the energy transfer process was determined to involve quadrupole quadrupole interaction. We have also studied the energy transfer from Tb3+-->Pr3+ when both the rare earths are doped together in the glass. A decrease in the lifetime of the 5D4 level of Tb3+ with the increase of Pr3+ concentration confirms this.     

Dinuclear 3D metal complexes based on a carbacylamidophosphate ligand: redetermination of the ligand crystal structure

Dinuclear Ni(II), Co(II) and Zn(II) complexes of general formula $ \left[ {{\text{M}}_{ 2}^{\text{II}} {\text{Cl}}_{ 4} \left( {\text{HL}} \right)_{ 4} \left( {\text{i-PrOH}} \right)_{ 2} \cdot 2\left( {\text{i-PrOH}} \right)} \right] $ with a carbacylamidophosphate ligand, namely 2,2,2-trichloro-N-(dipiperidine-1-yl-phosphoryl)acetamide (CCl₃C(O)N(H)P(O)[N(CH₂)₅]₂), were synthesized and characterized by physicochemical and spectroscopic methods. Electronic absorption spectra of the nickel and cobalt complexes were measured at room temperature in toluene and in the solid state. The crystal structures of HL and [Ni₂Cl₄(HL)₄(i-PrOH)₂·2(i-PrOH)] have been determined by single-crystal XRD studies. Earlier, the structure of a monoclinic C2/c modification of HL was reported. In this paper, redetermination of the structure of HL with triclinic crystal system, P $ \overline{1} $ , was made. The nickel complex is a chloro-bridged dimer, in which the Ni(II) centers are in a distorted octahedral geometry and the neutral HL is coordinated via its phosphoryl oxygen atom. This coordination mode was determined for the first time for 3D metal carbacylamidophosphate complexes.     

Investigations into the synthesis and fluorescence properties of Tb(III) complexes of a novel bis-beta-diketone-type ligand and a novel bispyrazole ligand

A novel bis-beta-diketone organic ligand, 1,1'-(2,6-bispyridyl)bis-3-(p-methoxyphenyl)-1,3-propanedione (L1) and its derivatives, a novel bispyrazole ligand, 2,6-bis(5-(4-methoxyphenyl)-1H-pyrazol-3-yl)pyridine (L2) were designed and synthesized and their complexes with Tb(III) ion were successfully prepared. The ligands and the corresponding metal complexes were characterized by elemental analysis, infrared, proton nuclear magnetic resonance spectroscopy and TG-DTA. Analysis of the IR spectra suggested that the lanthanide metal ion Tb(III) coordinated to the ligands via the nitrogen atom of the pyridine ring and the carbonyl oxygen atoms for ligand L1 and the nitrogen atom of the pyrazole ring for ligand L2. The fluorescence properties of the two complexes in solid state were investigated and it was discovered that the Tb(III) ions could be sensitized by both the ligand (L1) and ligand (L2) to some extent. In particular, the complex of ligand (L2) is a better green luminescent material that could be used as a candidate material in organic light-emitting devices (OLEDs) since it could be much better sensitized by the ligand (L2), and the fluorescence intensity of Tb(III) complex of L2 are almost as twice strong as L1's.     

KMgF3:Ce3+,Tb3+纳米粒子中Ce3+→Tb3+的发光及能量传递

利用微乳液方法,合成了铈、铽共掺杂的氟镁钾纳米粒子,研究了体系中Ce3+→Tb3+的发光特性以及它们之间的相互作用,结果表明KMgF3:Ce3+Tb3+纳米粒子中存在Ce3+→Tb3+的能量传递过程,即Ce3+可以将吸收的能量直接传递给Tb3+离子,使得Tb3+的绿色发光强度大为增加.     

Spectroscopic studies of interactions involving horseradish peroxidase and Tb3+

The spectroscopic properties of interactions involving horseradish peroxidase (HRP) and Tb(3+) in the simulated physiological solution was investigated with some electrochemical and spectroscopic methods, such as cyclic voltammetry (CV), circular dichroism (CD), X-ray photoelectron spectroscopy (XPS) and synchronous fluorescence (SF). It was found that Tb(3+) can coordinate with oxygen atoms in carbonyl groups in the peptide chain of HRP, form the complex of Tb(3+) and HRP (Tb-HRP), and then lead to the conformation change of HRP. The increase in the random coil content of HRP can disturb the microstructure of the heme active center of HRP, in which the planarity of the porphyrin cycle in the heme group is increased and then the exposure extent of the electrochemical active center is decreased. Thus Tb(3+) can inhibit the electrochemical reaction of HRP and its electrocatalytic activity for the reduction of H(2)O(2) at the Au/Cys/GC electrode. The changes in the microstructure of HRP obstructed the electron transfer of Fe(III) in the porphyrin cycle of the heme group, thus HRP catalytic activity is inhibited. The inhibition effect of Tb(3+) on HRP catalytic activity is increased with the increasing of Tb(3+) concentration. This study would provide some references for better understanding the rare earth elements and heavy metals on peroxidase toxicity in living organisms.     

Tb3+/Eu3+镧系金属有机框架材料在荧光检测的研究进展

镧系金属有机骨框架（Lanthanide metal organic frameworks,Ln-MOFs）是以镧系离子为中心,与配体有机物组合的多孔材料,具有良好的光学性质,在许多领域有广泛的应用。不同的镧系离子与相应的有机配体结合,可组成不同性能的Ln-MOFs。在众多镧系元素中,Tb3+和Eu3+是良好的发光中心,常被用于组建发光Ln-MOFs。由Tb3+/Eu3+与有机配体形成的Ln-MOFs具有独特的荧光特性、较大stokes位移以及长发光寿命等优点在荧光检测领域具有重要应用。本文综述了基于Tb3+/Eu3+的Ln-MOFs在离子检测、生物标志物检测以及小分子检测领域的研究进展,对Ln-MOFs的发展前景进行了展望。     

Tb~(3+)在YAG中的发光及Tb~(3+)与Tm~(3 +)间的能量传递

采用溶胶 -凝胶方法合成了系列化合物 (Y1 -x- yTbxTmy) 3Al5O1 2 ,研究了Tb3+在该化合物中的发光及其浓度对发光性质的影响 ,以及Tb3+与Tm3+间的能量传递现象。     

Magnetism of cyano-bridged Ln3+-M3+ complexes. Part II: one-dimensional complexes (Ln3+ = Eu, Tb, Dy, Ho, Er, Tm; M3+ = Fe or Co) with bpy as blocking ligand

The reaction of Ln(NO3)3(aq) with K3[Fe(CN)6] or K3[Co(CN)6] and 2,2'-bipyridine in water/ethanol led to 13 one-dimensional complexes: trans-[M(CN)4(mu-CN)2Ln(H2O)4(bpy)]n.4nH2O.1.5nbpy (Ln = Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Lu3+; M = Fe3+, Co3+). The structures for [EuFe]n (1), [TbFe]n (2), [DyFe]n (3), [HoFe]n (4), [ErFe]n (5), [TmFe]n (6), [LuFe]n (7), [EuCo]n (8), [TbCo]n (9), [DyCo]n (10), [HoCo]n (11), [ErCo]n (12), and [TmCo]n (13) have been solved: they crystallize in the triclinic space group P and are isomorphous. They exhibit a supramolecular architecture created by the interplay of coordinative, hydrogen bonding, and pi-pi interactions. A stereochemical study of the eight-vertex polyhedra of the lanthanide ions, based on continuous shape measures, is presented. The Ln3+-Fe3+ interaction is antiferromagnetic in [DyFe]n and [TbFe]n. For [EuFe]n, [HoFe]n, [ErFe]n, and [TmFe]n, there is no sign of any significant interaction. The magnetic behavior of [DyFe]n suggests the onset of weak long-range ferromagnetic ordering at 2.5 K.     

Tunable luminescence and energy transfer process between Tb3+ and Eu3+ in GYAG:Bi3+, Tb3+, Eu3+ phosphors

A series of Eu³⁺ ions co-doped (Gd_0.9Y_0.1)₃Al₅O₁₂:Bi³⁺, Tb³⁺ (GYAG) phosphors have been synthesized by means of solvothermal reaction method. The XRD pattern of GYAG phosphor sintered at 1500 °C confirms their garnet phase. The luminescence properties of these phosphors have been explored by analyzing their excitation and emission spectra along with their decay curves. The excitation spectra of the GYAG:Bi³⁺, Tb³⁺, Eu³⁺ phosphors consists of broad bands in the shorter wavelength region due to 4f⁸ → 4f⁷5d¹ transition of Tb³⁺ ions overlapped with 6s² → 6s¹6p¹ (¹S₀ → ³P₁) transition of Bi³⁺ ions and the charge transfer band of Eu³⁺–O^2?. The present phosphors exhibit green and red colors due to ⁵D₄ → ⁷F₅ transition of Tb³⁺ ions and ⁵D₀ → ⁷F₁ transition of Eu³⁺ ions, respectively. The emission was shifted from green to red color by co-doping with Eu³⁺ ions, which indicate that the energy transfer probability from Tb³⁺ to Eu³⁺ ions are dependent strongly on the concentration of Eu³⁺ ions.     

2,2'-bipyridine lariat calixcrowns: a new class of encapsulating ligands forming highly luminescent Eu3+ and Tb3+ complexes

A new class of calix[4]arene crown ethers with one or two bipyridines appended to the polyether ring (lariat calixcrowns) have been designed and synthesized; the luminescence properties of their Eu3+ and Tb3+ complexes have been studied in acetonitrile. In this solvent, long lifetimes for the metal emitting states and high metal-luminescence intensities obtained upon ligand excitation have been observed in both Eu3+ and Tb3+ complexes. The association constants in methanol have been determined for some of the complexes studied.     

Rare earth complexes chemiluminescence catalyzed by gold nanoparticles for fast sensing of Tb3+ and Eu3+

Developing multiplex sensing technique is of great significance for fast sample analysis. However, the broad emissions of most chemiluminescence(CL) luminophores make the multiplex CL analysis be difficult. In this work, a simple and sensitive CL analytical method has been developed for the simultaneous determination of Tb³⁺and Eu³⁺thanking to their narrow band emission. The technique was based on a mixed CL system of periodate(IO₄^-)-hydrogen peroxide(...     

Adsorption and luminescence properties of Tb3+-modified perfluorosulfonic acid membrane

After treatment of perfluorosulfonic acid membrane MF-4SK with an aqueous solution of TbCl₃, the protons in sulfo groups are completely replaced by the hydrated terbium cations. Specific features of the water adsorption and its influence on the luminescence of the modified membrane were examined.