稀土机配合物电致发光研究进展

稀土配合物发射带窄,发射光谱具有类原予光谱性质,色纯度高(半宽峰<10 nm),非常适合于全彩色显示.另外,稀土配合物发光效率高,理论上内量子效率可达100%.因此,稀土配合物是全色平板显示器件中理想的发光材料之一,研究稀土配合物电致发光性质具有重要的实际意义和理论意义.以稀土镧系离子配合物作为发光中心的电致发光器件的研究主要集中于发光效率比较高的Eu3+,Tb3+以及近红外的Nd3+,Yb3+和Er3+离子.分类综述了近年稀土配合物电致发光研究的成果及其进展.总结了不同类型的铕配合物、铽配合物的电致发光特性,证明配体对于稀土离子的敏化作用非常重要;总结了近红外的镱、钕、铒配合物在光放大、激光技术、生物医学等方面的潜在应用价值.     

稀土配合物在有机电致发光器件中的应用

作为一类特殊的发光材料,稀土配合物是全彩平板显示器件中理想的发光材料之一,具有独特的优势和重要的地位,因而最早引起了研究人员的广泛关注.本文综述了近年来新型稀土铕、铽配合物的设计合成与基于稀土铕、铽配合物电致发光器件的设计优化,总结了优化稀土配合物电致发光性能的几种常用途径,进而着重介绍了稀土铕、铽、钆配合物作为敏化剂在有机电致发光器件中的新应用.研究结果表明,稀土配合物作为敏化剂的应用能够实现稀土配合物与过渡金属配合物的优势互补,大幅提高了有机电致发光器件的综合性能,为新型高性能有机电致发光器件的设计与优化提供了新思路.     

Sm(DBM)3phen的光致发光和电致发光性质

制备了一系列基于配合物Sm(DBM)3phen的电致发光器件. 研究了其光致发光(PL)和电致发光(EL)性质, 实验结果表明, Sm(DBM)3phen具有良好的电子注入和传输性能以及电致发光性能. 器件ITO/TPD(50 nm)/Sm(DBM)3phen(50 nm)/Alq3(30 nm)/LiF(1.0 nm)/Al的最大亮度和最大效率分别为150 cd/m2和0.72 cd/A, 器件表现为纯Sm3+离子的发光.     

铽配合物TbY(o-MBA)6(phen)2与PVK掺杂体系的发光性质研究

合成了一种新型的稀土铽配合物材料TbY(o-MBA)6(phen)2,把它作为发光材料应用于有机电致发光中.把铽配合物掺杂在导电聚合物PVK中采用旋涂法制得发光层,并利用AlQ作为电子传输层制作了多种结构的电致发光器件 器件A,ITO/PVK∶TbY (o-MBA)6(phen)2/LiF/Al;器件B,ITO/PVK∶TbY (o-MBA)6(phen)2/AlQ/LiF/Al;器件C,ITO/PVK∶TbY (o-MBA)6(phen)2/BCP/AlQ/LiF/Al.对器件A和B得到了纯正的、明亮的Tb3+离子的绿光发射,4个特征峰分别对应着能级5D4到7Fj(j=6,5,4,3)的跃迁,而PVK的发光完全被抑制.研究了掺杂体系的光致发光性能和电致发光性能,认为在光致发光中,铽的发光主要来源于PVK到稀土配合物的Frster能量传递.而在电致发光中,铽的发光主要来源于稀土配合物直接捕获载流子形成激子复合发光.并通过优化选择得到了发光性能较好的器件B,其最大亮度在14 V时达到213 cd·m-2.     

近红外发光稀土配合物及杂化材料研究进展

稀土因其特殊的物理和化学性质,在信息技术、能源技术、生物技术等高科技领域及国防建设等方面都起着非常重要的作用,中国作为稀土大国,十分重视对稀土材料的研究和开发。稀土离子近红外发光(750～1700 nm)在激光和光纤通讯、医学诊断、免疫分析等热门领域的潜在应用,受到了科研人员的极大关注。稀土离子本身发光极弱,通过分子内传能有机配体可以敏化稀土离子发光,但稀土配合物常受外界干扰,其稳定性较差,若将其与凝胶、介孔材料、离子液体等无机基质复合,得到具有良好光、热稳定性和化学稳定性的有机/无机杂化材料。总结了近些年来近红外发光稀土配合物及近红外发光稀土杂化材料的研究进展,并对其发展前景进行了展望。     

小分子配合物电致发光材料研究进展

本文简述了有机电致发光及有机发光二极管的基本原理 ;概述了小分子配合物电致发光材料的最新研究进展 ,讨论了它们的光电性质、器件的发光效率和稳定性 ;展望了小分子配合物电致发光材料的前景.     

噻吩甲酰三氟丙酮—酰基吡唑啉酮—邻菲咯啉合铕（Ⅲ）四？…

近年来 ,稀土金属螯合物因其发光色度纯 ,荧光量子效率高 (理论可达 1 0 0 % ) ,在有机电致发光平板显示器研究中得到广泛应用[1～ 3] .用噻吩甲酰三氟丙酮作为配阴离子与稀土离子Ｅｕ3+配位 ,可得到红色电致发光材料[4～ 6] .为提高这类配合物的电致发光强度和发光效率 ,增强配体与稀土离子间的敏化作用 ,改善配合物的载流子传输性和成膜性十分重要 .本文利用配阴离子 4 叔丁基苯甲酰基吡唑啉酮 (ＨＰＭＴＢＢＰ)和噻吩甲酰三氟丙酮 (ＨＴＴＡ)和中性配体 1 .1 0 邻菲咯啉 (Ｐｈｅｎ)与铕 (Ⅲ )作用 ,合成了铕 (Ⅲ )四元配合物 [Ｅｕ(ＴＴ…     

稀土铽配合物有机电致发光

利用三价稀土铽配合物作为发射层、二胺衍生物(TPD)以及聚乙烯咔唑(PVK)作为空穴传输层制备了有机电致发光器件. 器件的结构为 玻璃衬底/ITO/PVK 或者TPD/Tb3+ 配合物/Al, 其中空穴传输层TPD 和发光层Tb3+-配合物采用热蒸发办法成膜. 而空穴传输层PVK采用旋甩涂敷的方法成膜. 对于以上的两种器件均获得了来自Tb3+ 的窄峰发射, 在直流电压15.4 V驱动下, 器件发光亮度达210 cd·m-2.     

d-f跃迁发光稀土配合物研究进展

稀土配合物独特的发光性质使其在众多领域有很大的应用价值。其中, d-f跃迁发光稀土配合物具有跃迁宇称允许、激发态寿命短和光谱可调等特点,但相关研究还有待进一步深入。本文介绍了稀土配合物的发光机制,综述了具有d-f跃迁发光性质的稀土配合物(主要是Ce³⁺, Eu²⁺, Yb²⁺和Sm²⁺配合物)的研究进展,并初步总结了配合物分子结构对d-f跃迁发光性质的影响规律。     

Sm(TTA)3phen的摩擦发光及发光现象与配体性质的关系研究

发现了Sm(TTA)3phen的摩擦发光现象(TL), 并对其TL光谱进行了表征. 实验结果显示, TL仍属于Sm3+离子的特征发射. 研究了稀土配合物摩擦发光现象与配体性质之间的关系, 发现配体分子的结构和性质对稀土配合物的TL性质有重要的影响: 具有强电子给体-受体(D-A)体系的配体分子有利于形成摩擦发光配合物, 且配体分子应具有一定的刚性, 从而有利于配合物形成良好的晶体.     

Responsive lanthanide luminescent cyclen complexes: from switching/sensing to supramolecular architectures

This article highlights some of the recent developments in the use of responsive cyclen based lanthanide luminescent devices, focusing on Eu(III), Tb(III), Nd(III) and Yb(III) complexes, where the photophysical properties, such as the excited state lifetimes, quantum yield/intensity and emission polarisation are modulated by the local chemical environment, e.g. ions and molecules, or through self-assembly of either f-f or mixed f-d cyclen complexes.     

Luminescent lanthanide ions hosted in a fluorescent polylysin dendrimer. Antenna-like sensitization of visible and near-infrared emission

We have investigated the complexation of the luminescent Nd(3+), Eu(3+), Gd(3+), Tb(3+), Er(3+), and Yb(3+) ions by a polylysin dendrimer containing 21 amide groups in the interior and, in the periphery, 24 chromophoric dansyl units which show an intense fluorescence band in the visible region. Most of the experiments were performed in 5:1 acetonitrile/dichloromethane solution at 298 K. On addition of the lanthanide ions to dendrimer solutions, the fluorescence of the dansyl units is quenched; in Nd(3+), Er(3+), and Yb(3+), a sensitized near-infrared emission of the lanthanide ion is observed. At low metal ion concentrations, each dendrimer hosts only one metal ion and when the hosted metal ion is Nd(3+) or Eu(3+), the fluorescence of all the 24 dansyl units of the dendrimer is quenched with unitary efficiency. Quantitative measurements were performed in a variety of experimental conditions, including protonation of the dansyl units and measurements in rigid matrix at 77 K where a sensitized Eu(3+) emission could also be observed. The results obtained have been interpreted on the basis of the energy levels and redox potentials of dendrimer and metal ions.     

Preparation, characterization and luminescent properties of lanthanide complexes with a new aryl amide bridging ligand

A new aryl amide type bridging ligand 1,4-bis{[(2'-benzylaminoformyl)phenoxyl]ethoxyl}benzene (L) and its complexes with lanthanide ions (Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er) were synthesized and characterized by elemental analysis, infrared spectra and electronic spectra. At the same time, the luminescent properties of the Sm, Eu, Tb and Dy complexes in solid state and the Tb complex in solvents were also investigated. At room temperature, these four complexes exhibited characteristic luminescence emissions of the central metal ions under UV light excitation and could be significant in the field of supramolecular photonic devices.     

Synthesis and luminescence properties of lanthanide complexes incorporating a hydralazine-derived chromophore

Reaction of 1-hydrazinophthalazine with chloroacetyl chloride yields 3-chloromethyl-1,2,4-triazolo-phthalazine. Reaction of this product with the tris tert-butyl ester of DO3A yields a triazolophthalazine appended macrocycle. Hydrolysis and complexation with lanthanide ions gives access to a series of lanthanide complexes (Ln = Nd, Eu, Yb, Er); these are all luminescent and exhibit sensitisation of the lanthanide centre by the chromophore.     

Syntheses, structures and properties of seven isomorphous 1D Ln3+complexes Ln(BTA)(HCOO)(H2O)3 (H2BTA = bis(tetrazoly)amine, Ln = Pr, Gd, Eu, Tb, Dy, Er, Yb) and two 3D Ln3+ complexes Ln(HCOO)3 (Ln = Pr, Nd)

Seven isomorphous 1D chain Ln3+ complexes Ln(BTA)(HCOO)(H2O)3 (Ln = Pr (1), Gd (2), Eu (3), Tb (4) Dy (5), Er (6) and Yb (7)), and two formate coordinating and bridging 3D Ln3+ complexes Ln(HCOO)3 (Ln = Pr (8) and Nd (9)) have been synthesized and characterized by single crystal X-ray diffraction analysis. Although the Ln3+ ions in 1-7 have different radius, the trivalent lanthanide ions in 1-7 show the same coordinated environment. The well-defined single crystal structures of 8 and 9 are first samples for formate-bridged Ln3+ metallic complexes. The luminescent properties of solid samples of 2-5 at room temperature and the magnetic property of 2 have been also reported and discussed in this paper.     

A water-soluble Pybox derivative and its highly luminescent lanthanide ion complexes

A new water-soluble Pybox ligand, 1, has been synthesized and found to crystallize in the monoclinic P2(1)/n space group with unit cell parameters a = 6.0936(1) ?, b = 20.5265(4) ?, c = 12.0548(2) ?, and β = 90.614(1)°. In the crystal, a water molecule is bound through hydrogen-bonding interactions to the nitrogen atoms of the oxazoline rings. This ligand was used to complex a variety of lanthanide ions, opening up new avenues for luminescence and catalysis in aqueous environment. These complexes are highly luminescent in aqueous solutions, in acetonitrile, and in the solid state. Aqueous quantum yields are high at 30.4% for Eu(III), 26.4% for Tb(III), 0.32% for Yb(III), and 0.11% for Nd(III). Er(III) did not luminesce in water, but an emission efficiency of 0.20% could be measured in D(2)O. Aqueous emission lifetimes were also determined for the visible emitting lanthanide ions and are 1.61 ms for Eu(III) and 1.78 ms for Tb(III). Comparing emission lifetimes in deuterated and nondeuterated water indicates that no water molecules are coordinated to the metal ion. Speciation studies show that three species form successively in solution and the log β values are 5.3, 9.6, and 13.8 for Eu(III) and 5.3, 9.2, and 12.7 for Tb(III) for 1:1, 2:1, and 3:1 ligand to metal ratios, respectively.     

Highly uniform and monodisperse beta-NaYF(4):Ln(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) hexagonal microprism crystals: hydrothermal synthesis and luminescent properties

beta-NaYF4:Ln3+ (Ln = Eu, Tb, Yb/Er, and Yb/Tm) hexagonal microprisms with remarkably uniform morphology and size have been synthesized via a facile hydrothermal route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. It is found that sodium citrate as a shape modifier introduced into the reaction system plays a critical role in the shape evolution of the final products. Furthermore, the shape and size of the products can be further manipulated by adjusting the molar ratio of citrate/RE3+ (RE represents the total amount of Y3+ and the doped rare earth elements such as Eu3+, Tb3+, Yb3+/Er3+, or Yb3+/Tm3+). Under the excitation of 397 nm ultraviolet light, NaYF4:xEu3+ (x = 1.5, 5%) shows the emission lines of Eu3+ corresponding to 5D0-3 --> 7FJ (J = 0-4) transitions from 400 to 700 nm (whole visible spectral region) with different intensity, resulting in yellow and red down-conversion (DC) light emissions, respectively. When doped with 5% Tb3+ ions, the strong DC fluorescence corresponding to 5D4 --> 7FJ (J = 6, 5, 4, 3) transitions with 5D4 --> 7F5 (green emission at 544 nm) being the most prominent group that has been observed. In addition, under 980 nm laser excitation, the Yb3+/Er3+- and Yb3+/Tm3+-codoped beta-NaYF4 samples exhibit bright green and whitish blue up-conversion (UC) luminescence, respectively. The luminescence mechanisms for the doped lanthanide ions were thoroughly analyzed.     

Highly resolved luminescence measurements for traces of 1,3-dibetanato europium(III) and terbium(III) complexes using a microscope laser Raman spectrometer toward the forensic discrimination.

The emission spectra of luminescent trivalent europium (Eu3+) and terbium (Tb3+) complexes were measured using a microscope laser Raman spectrometer with a doubled Nd:YAG laser (532 nm) and an Ar laser (488 nm). Excitation at 532 and 488 nm corresponded to wavelengths of the 7F1 --> 5D1 band of Eu3+ and the 7F6 --> 5D4 band of Tb3+, respectively. The Eu3+ and Tb3+ complexes were discriminated by high-resolution emission spectra more distinctly and sensitively than by fluorescence spectrometry, the usual analytical method.     

Luminescent ruthenium(II) bipyridine-calix[4]arene complexes as receptors for lanthanide cations

The synthesis and photophysical properties of novel luminescent ruthenium(II) bipyridyl complexes containing one, two, or six lower rim acid-amide-modified calix[4]arene moieties covalently linked to the bipyridine groups are reported which are designed to coordinate and sense luminescent lanthanide ions. All the Ru-calixarene complexes synthesized in this work are able to coordinate Nd(3+), Eu(3+), and Tb(3+) ions with formation of adducts of variable stoichiometry. The absorbance changes allow the evaluation of association constants whose magnitudes depend on the nature of the complexes as well as on the nature of the lanthanide cation. Lanthanide cation complex formation affects the ruthenium luminescence which is strongly quenched by Nd(3+) ion, moderately quenched by the Eu(3+) ion, and poorly or moderately increased by the Tb(3+) ion. In the case of Nd(3+), the excitation spectra show that (i) the quenching of the Ru luminescence occurs via energy transfer and (ii) the electronic energy of the excited calixarene is not transferred to the Ru(bpy)(3) but to the neodymium cation. In the case of Tb(3+), the adduct's formation leads to an increase of the emission intensities and lifetimes. The reason for this behavior was ascribed to the electric field created around the Ru calix[4]arene complexes by the Tb(3+) ions by comparison with the Gd(3+) ion, which behaves identically and can affect ruthenium luminescence only by its charge. However, especially for compounds 1 and 3, it cannot be excluded that some contribution comes from the decrease of vibrational motions (and nonradiative processes) due to the rigidification of the structure upon Tb(3+) complexation. In the case of Eu(3+), compounds 1, 2, and 4 were quenched by the lanthanide addition but the quenching of the ruthenium luminescence is not accompanied by europium-sensitized emission which suggests that an electron-transfer mechanism is responsible for the quenching. On the contrary, compound 3 exhibits enhanced emission upon addition of Eu(3+) (as nitrate salt); it is suggested that the lack of quenching in the [3.2Eu(3+)] adduct is due to kinetic reasons because the electron-transfer quenching process is thermodynamically allowed.