稀土与对硝基苯乙酸配合物的合成、表征及荧光性质

本文合成了三种稀土与对硝基苯乙酸 (HL)的二元固体配合物 ,通过元素分析等手段确定了其配合物的组成为ReL3·H2 O(Re=Eu ,Sm ,Tb)。用红外光谱、紫外光谱、荧光光谱对该类配合物的结构与性质进行了表征。红外谱表明配体以—COO- 形式与中心离子配位 ,同时这一点也被自由配体和配合物的UV谱所证实。EuL3·H2 O的强红色荧光分属于Eu3+ 的 5D0 → 7F1 和5D0 → 7F2 跃迁。     

稀土三元配合物粉末和凝胶共发光效应的光声光谱研究

合成了Eu(TTA) 3 ·Phen和Eu0 .8Y0 .2 (TTA) 3 ·Phen固体配合物微晶粉末及其掺杂的SiO2 凝胶样品 .在30 0～ 80 0nm测定并解释了其光声光谱 .在配体吸收处 ,Eu0 .8Y0 .2 (TTA) 3 ·Phen的光声强度低于Eu(TTA) 3 ·Phen的光声强度 ;而对于配合物掺杂的凝胶样品 ,则情况相反 .Y3 + 的引入改变了配合物的弛豫过程 ,且配合物在粉末和凝胶状态下 ,弛豫历程不尽相同 .结合荧光光谱研究了标题化合物的发光特性 ,并建立了能量传递模型 .     

稀土配合物分子内能量传递和弛豫过程的光声和荧光光谱研究

将光声光谱和荧光光谱两种互补的手段结合起来 ,从无辐射跃迁和辐射跃迁两个角度讨论了固态稀土配合物的激发 弛豫过程。测定了稀土配合物 (Tb(AA) 3·2H2 O、Tb(AA) 3bpy和Tb(AA) 3phen)固体粉末的光声光谱和荧光光谱。与荧光光谱相结合 ,光声光谱反映了不同配合物发光效率的变化 ,Tb(AA) 3phen、Tb(AA) 3·2H2 O和Tb(AA) 3bpy的发光效率依次增强。研究了配合物的分子内能量传递和弛豫过程 ,配体最低三重态能级与稀土离子共振能级之间的能级差是否匹配是配体敏化中心离子发光的关键因素     

Co(Ⅲ)联吡啶配合物的合成及紫外光谱研究

合成了钴多吡啶配合物Co(bpy)3(ClO4)3,通过紫外光谱对该配合物进行了表征.光谱结果显示中心离子与配位体的相互作用使配合物与联吡啶的吸收光谱发生位移.     

镧系离子(Eu3+,Tb3+)氧氟沙星配合物的合成和光谱表征

本文报道了镧系离子Eu3 + ,Tb3 + 同喹诺酮羧酸类衍生物氧氟沙星形成配合物的合成。用元素分析法和ICP确定了配合物的组成为Ln(oflo) 3 Cl3 ·8H2 O。红外光谱表明氧氟沙星配体羧基同中心离子发生螯合 ,并可能与邻位羰基形成六元环稳定结构。荧光光谱表明 ,Eu配合物具有很宽的激发谱带 (2 0 0～ 45 0nm) ,明显区别于其他羧酸类的稀土配合物 ;中心离子Eu3 + 发射谱位于 5 79 0nm(5D0 7F0 ) ,5 92 2nm(5D0 7F1) ,6 12 2nm(5D0 7F2 ) ;而Tb3 + 配合物则同时有配体和中心离子的荧光发射     

Eu(p-PBA)3phen1/2H2O的高分辨光谱和Raman光谱

配合物Eu(p-PBA)3phen1/2H2O(p-PBA:对苯基苯甲酸酸根离子;phen:邻菲咯啉)在紫外光激发下,能发出很强的红色荧光.以Eu(Ⅲ)离子为光谱探针,77K下测得其高分辨激发和发射光谱,选择激发配合物的5D0能级,得到两组不同的发光光谱,表明配合物中Eu(Ⅲ)离子有两种不同的化学环境.配合物的喇曼光谱中,羧基阴离子的反对称伸缩振动和对称伸缩振动谱带是明显分裂和带肩峰的宽带,说明配合物中羧基同时存在多种配位方式.     

稀土邻菲咯啉双核配合物的光谱研究

合成了 Yx Eu1-x(phen) 2 Cl3· n H2 O、Tbx Eu1-x(phen) 2 Cl3· n H2 O(x=0、0 .2 5、0 .5 0、0 .75 )固体配合物 ,并测定了红外光谱、荧光发射光谱 ,讨论了配合物的组成与发光特性     

Eu(o-MBA)3phen配合物的荧光光谱和喇曼光谱

配合物Eu(o-MBA)3phen(o-MBA:邻甲基苯甲酸酸根离子;phen:1,10-二氮杂菲)在紫外或可见光激发下,能发出很强的红色荧光.以Eu(Ⅲ)离子为光谱探针,77K下测得其高分辨激发和发射光谱.选择激发配合物的5D0能级,得到两组不同的5D0→7F2发光光谱,表明配合物中Eu(Ⅲ)离子有不同的化学环境.配合物的喇曼光谱中,羧基阴离子的反对称伸缩振动(γas(COO))和对称伸缩振动(γs(COO))谱带是明显分裂和带肩峰的宽带,说明配合物中羧基同时存在多种配位方式,这与它的晶体结构测定结果一致.     

铕-2-羟基喹啉-4-羧酸配合物的合成及光谱性能

以Eu3+为中心离子,2-羟基喹啉-4-羧酸(H2hqc)、1,10-菲罗啉(Phen)和三苯基氧磷(TPPO)为配体,合成了新型配合Eu(Hhqc)3(H2O)、Eu(Hhqc)3Phen(H2O)5和Eu(Hhqc)3TPPO(H2O)5.用元素分析和红外光谱对配合物进行了表征,IR表明配合物Eu(Hhqc)3Phen(H2O)5的Δν值大于钠盐Δν值,配合物中羧酸根以单齿方式配位.而配合物Eu(Hhqc)3(H2O)和Eu(Hhqc)3TPPO(H2O)5Δν值均小于钠盐的Δν值,表明配合物中羧酸根与Eu3+呈螯合双齿配位方式.室温下测定了配合物的荧光光谱,研究了它们的荧光性能.结果表明,配合物均在581,594,615,654和703nm附近产生五条谱带,为Eu3+的特征发射,归属为5 D0→7 FJ(J=0,1,2,3,4)能级间的跃迁,第二配体Phen和TPPO的引入对Eu3+的荧光发射有明显增强作用,且Phen效果更好.     

铕与苯甲酸、邻菲啰啉系列配合物的合成和光谱分析

合成了铕与苯甲酸(BA)二元配合物及铕与BA、邻菲啰啉(Phen)三元配合物,研究了配合物的红外、紫外吸收光谱及荧光光谱.紫外光谱的研究表明,配合物的紫外吸收主要表现为配体的吸收,配体吸收能量传递给中心离子Eu3+.配合物红外光谱不同于配体的红外光谱,羧基的对称伸缩振动vm (coo-)移至1418cm-1,反对称伸缩振动vaa(COO-)移至1562cm-1,表明稀土与配体之间形成了配位键;测定了配合物及其防伪油墨的荧光性能,铕与苯甲酸、邻菲啰啉形成的三元配合物表现出中心离子Eu3+的特征荧光,616nm荧光发射最强谱蜂对应Eu3+的5D0→7F2跃迁.制备的稀土荧光防伪油墨在可见光下印迹无色,在紫外灯下呈现明显红色荧光.     

Study of Conformers of 6,6'-Dimethyl-2,2'-bipyridine in the Ground and Excited States

UV absorption, luminescence, and luminescence-excitation spectra of the trans and metal-free cis conformers of 6,6'-dimethyl-2,2'-bipyridine (6,6'-Me₂bpy) and its Zn²⁺ complex have been observed in 2-propanol and 2-propanol-water mixtures at 77 K. The stable conformation of 6,6'-Me₂bpy in the ground state depends on the composition of the mixture at 77 K and the conformation remains unchanged upon photoexcitation. The lowest excited sing let energy is sensitive to the coordination to Zn²⁺, while the fluorescence lifetime is sensitive to both the conformation change of 6,6'-Me₂bpy and to the coordination to Zn²⁺.     

Spectroscopic studies on the luminescence properties of ternary europium complexes with different ligands

In this paper, ligand effect of several bi-dental oxygen (O) and nitrogen (N) ligands on the red luminescence properties of europium ion (Eu³⁺) was studied comprehensively. Absorption, emission, and excitation spectral properties of ternary europium complexes with different combinations of ligands including thenoyl trifluoroacetone (TTA), naphthyl trifluoroacetone (NTA), 2,2′-bipyridyl (bpy) and phenanthroline (Phen) were investigated. Efficient Eu³⁺ red emission was observed with all the combinations of the above mentioned ligands. The most intense emission was found with the all nitrogen coordinated complex Eu(bpy)₂(Phen)₂ while the longest wavelength excitation band was recorded with oxygen-nitrogen mixed NTA-bpy complex Eu(NTA)₁(bpy)₃. With change of the ligands combination and ratio, the Eu³⁺ emission peak changes slightly from 612 to 618 nm. The absorption and excitation spectra of the europium complexes were compared and analyzed referring to the individual absorption spectral properties of the ligands. The relation between ligand-to-metal charge transfer states and luminescence intensities for different complexes was studied.     

Crystal Structure,Luminescence, and Triboluminescence of the Complex [Eu2(Quin)42H2O2Dipy]2(NO3)2H2O

Optics and Spectroscopy - An atomic structure of crystals of the complex [Eu2(Quin)42Н2O2Dipy]2 · 2(NO3) · Н2O, (Quin, anion of quinaldic acid; Dipy, 2,2'-dipyridyl),...     

ARF4(A=Na,K;R=La,Gd,Y,Lu)中Eu2+的光谱结构及其价态稳定性

Eu2+在ARF4(A=Na,K;R=La,Gd,Y,Lu)中的荧光光谱结构是由特征的d→f跃迁宽带发射和f→f跃迁尖峰发射组成,低温下线/带强度比明显增强;高纯氩气流中合成的样品,Eu2+的价态是稳定的。     

Hypersensitivity in the Luminescence and 4f?C4f Absorption Properties of Mono- and Dinuclear EuIII and ErIII Complexes Based on Fluorinated ??-Diketone and Diimine/ Bis-Diimine Ligands

The results of our investigation on the sensitized luminescence properties of three Eu(III) ??-diketonate complexes of the form [Eu₂(fod)₆(??-bpm)], [Eu(fod)₃(phen)] and [Eu(fod)₃(bpy)] and 4f?C4f absorption properties of their Er(III) analogues ( fod = anion of 6,6,7,7,8,8,8- heptafluoro-2,2-dimethyl-3,5-octanedione, bpm = 2,2??-bipyrimidine, phen = 1,10-phenanthroline and bpy = 2,2??-bipyridyl) in a series of non-aqueous solvents are presented. The Eu(III) complexes are highly luminescent and their luminescence properties (intensity and band shape) are sensitive to the changes in the inner coordination sphere of the Eu(III) ion. The luminescence intensity of the mononuclear complexes in pyridine is drastically decreased. The coordination structure of the complexes in pyridine is transformed into a more symmetrical one which results into a slow radiative rate of the emission from the complexes. The ancillary ligands, phen and bpy are found better co-sensitizers as compared to the bpm to sensitize Eu(III)-luminescence. The 4f?C4f absorption properties (oscillator strength and band shape) of the Er(III) complexes demonstrate that ⁴G_11/2 ?? ⁴I_11/2 and ²H_11/2 ?? ⁴I_15/2 hypersensitive transitions of Er(III) are very sensitive in some coordinating solvents which reflects complex?Csolvent interaction in solution. The hypersensitive transitions of [Er(fod)₃(phen)] remain unaffected in any of the solvents and this complex retains its bulk composition in solution. The erbium complexes as well as the Er(fod)₃ chelate are invaded by DMSO. This solvent enters the inner coordination sphere by replacing heterocyclic ligand and the complexes acquire similar structure [Er(fod)₃(DMSO)₂] in this solvent. The results reveal that the luminescence and absorption properties of lanthanide complexes in solution can be controlled by tuning the coordination structure through ancillary ligands and donor solvents. This work shall prove useful in designing new biological applications with such probes.     

一种新的Eu3+配合物有机薄膜电致发光

自从C. W. Tang[1]百次发表高效、高亮度双层结构有机薄膜电致发光(EL)器件以来,由于其驱动电压低、可做成大面积及制作工艺简单等优点,使其在平板显示和显像领域具有巨大应用潜力而成为研究热点.可是大多数有机小分子和聚合物材料制作的有机薄膜电致发光器件的发射光谱谱带很宽,半高宽一般在100nm-200nm,色纯度不好,不利于显示和显像.于是寻找场致发光谱带窄、亮度高的有机材料就显得非常重要.     

Thermoluminescence of γ-irradiated BaCa(SO4)2:Eu,Dy

In this paper, thermoluminescence (TL) studies of BaCa(SO₄)₂:Eu,Dy phosphor are reported. A microcrystalline sample of BaCa(SO₄)₂:Eu,Dy was prepared by a solid state diffusion method and the formation of the compound was confirmed by the X-ray diffraction study. Morphology of the phosphor was analyzed by scanning electron microscopy (SEM). The sample is found to have an average particle size of 5?µm. TL glow curves of the γ-irradiated samples with different concentrations of Eu and Dy were studied and compared with BaCa(SO₄)₂:Eu and BaCa(SO₄)₂:Dy. It has been found that a single peak was located at around 230°C with the highest TL intensity in BaCa(SO₄)₂:Eu,Dy which is eight times and two times more than singly Dy- and Eu-doped BaCa(SO₄)₂ phosphor, respectively. For TL analysis, BaCa(SO₄)₂:Eu,Dy (0.2?mol%, 1?mol%) is annealed at different temperatures ranging from 900°C to 1100°C. Analysis of the TL glow curve was carried out by a glow curve deconvoluted method. Trapping parameters (activation energy and frequency factor) of all TL glow curves were evaluated by Chen's peak shape method. A comparison of trapping parameters between BaCa(SO₄)₂:Eu,Dy; BaCa(SO₄)₂:Eu and BaCa(SO₄)₂:Dy phosphors at 900°C, 1000°C and 1100°C is also reported in this paper.     

Sensitive Spectrofluorimetric Study of the Interaction between Europium(III) and 1,2-Phenylenebis(azan-1-yl-1-ylidene) bis(methan-1-yl-1-ylidene)diphenol Schiff Base

A sensitive and selective spectrofluorimetric method has been developed for the rapid determination of europium(III). This method is based on the formation of nonluminous complex between Eu(III) and a Schiff base reagent N, N′-bis (salicylidene)-1,2-phenylenediamine (PABD) and measuring the fluorescence quenching of Eu(III)-PABD complex at λ_ex/em = 390/577 nm. The fluorescence intensity complex decreased linearly by increasing the Eu(III) concentration in the range of 1.0–13.0 μM. The optimum conditions for the complex formation were determined such as a pH .0 of borate buffer. The limits of detection (LOD) and quantification (LOQ) of Eu(III) were determined and found to be 0.217 and 0.653 μM, respectively. The maximum relative standard deviation of the method for an europium(III) standard of 6.0 μM was 2.07 % (n = 6). The proposed procedures could be applied successfully for the determination of the investigated metal ion in some spiked water samples with a good precision and accuracy compared to official and reported methods as revealed by t- and F-tests.     

Investigation of Europium (III)-Rutin Complex in Water-Ethanolic Solution

Abstract

The composition and the stability constant of Eu(III)-rutin complex were determined by suitable spectrophotometric methods and pH-metric measurements. The formation of a (Eu(C₂₇H₂₆O₁₆H₃)₂)⁺ complex whose concentration stability constant β₂ ranged from 10.59 at pH=5.0 to 7.21 at pH=8.0, was established. Spectrophotometric determination of Eu(III) by means of the reaction of complex formation with rutin, was investigated. It was found that Eu(III) can be determined in the range from 5×10^?6 to 7.5×10^?5M. All investigations were carried out with 70% ethanolic solutions at room temperature (20°C), whereas spectrophotometric investigations were performed in the presence of a buffer, at constant pH values and ionic strength (0.015). The determination of the complex composition was done at pH=5.6, and that of Eu(III) at pH=6.3.     

Preparation of polymer–rare earth complex using salicylic acid-containing polystyrene and its fluorescence emission property

Salicylic acid (SA) was first bonded onto the side chains of polystyrene (PS), obtaining functional macromolecule SAPS. Using the salicylic acid-containing polystyrene as a macromolecular ligand, a polymer–rare earth complex, SAPS–Eu(III), was prepared. The structure of SAPS–Eu(III) was characterized, and the fluorescence properties of SAPS–Eu(III) were mainly investigated. The experimental results show that the complex SAPS–Eu(III) has fine chemical stability because of the bidentate chelating effect of salicylic acid ligand. More important, the ligand SA on the side chains of PS can strongly sensitize the fluorescence emission of the center ion, Eu³⁺ ion, and it enables the complex SAPS–Eu(III) to produce the apparent “Antenna Effect”. In the diluted solution of the functional macromolecule SAPS, the formed complex SAPS–Eu(III) belongs to an intramolecular complex, or an intrachain complex. For the binary intramolecular complex SAPS–Eu(III), the apparent saturated coordination number of SA of SAPS towards Eu³⁺ ion is equal to 10, and here the binary intrachain complex SAPS–Eu(III) has the strongest fluorescence emission. On this basis, small-molecule 1,10-phenanthroline (Phen) acting as a co-ligand is added and the ternary complex SAPS–Eu(III)–Phen will be formed. As long as a small amount of Phen is added (in the molar ratio 1:1 (n(Phen):n(Eu))), the coordination of the two kinds of ligands, SA of SAPS and Phen, to Eu³⁺ ion will reach complete saturation, and here the fluorescence emission of the ternary complex will be further enhanced via the complementary coordination effect in comparison with that of the binary complex SAPS–Eu(III).