稀土与L-苯丙氨酸配合物的PH电位法及量热滴定法研究

本文在25℃和0.15mol.dm^-^3(NaCl)离子强度下, 用pH电位法和量热滴定法测定了十五个稀土元素(Y和除Pm外的镧系元素)与L-苯丙氨酸1:1配合物的稳定常数及热力学函数。L-苯丙氨酸通过-CO^-~2和-NH~2与稀土离子配位, 生成较稳定的1:1配合物。配合物稳定性呈"四分组效应"。配合物稳定性顺序中Y的位置向轻稀土方向移动。体系的熵变是配位反应驱动力。离子的去水化在配位反应中起重要作用。     

Synthesis of 10 nm β‐NaYF4:Yb,Er/NaYF4 Core/Shell Upconversion Nanocrystals with 5 nm Particle Cores

A new method is presented for preparing gram amounts of very small core/shell upconversion nanocrystals without additional codoping of the particles. First, ca. 5 nm β‐NaYF₄:Yb,Er core particles are formed by the reaction of sodium oleate, rare‐earth oleate, and ammonium fluoride, thereby making use of the fact that a high ratio of sodium to rare‐earth ions promotes the nucleation of a large number of β‐phase seeds. Thereafter, a 2 nm thick NaYF₄ shell is formed by using 3–4 nm particles of α‐NaYF₄ as a single‐source precursor for the β‐phase shell material. In contrast to the core particles, however, these α‐phase particles are prepared with a low ratio of sodium to rare‐earth ions, which efficiently suppresses an undesired nucleation of β‐NaYF₄ particles during shell growth.     

Terbium(III) as fluorescence probe in the study of the interaction of rare earth and transition metal ions with concanavalin A

The binding site for calcium (II) on concanavalin A (con-A) can be occupied by rare earth ions. When terbium (III) ion binds to con-A, its fluorescence intensity is tremendously enhanced because of an energy transfer from one or more tryptophan residues in close proximity to the bound terbium (III). The dissociation constant of the con-A-Tb (III) complex is 8.90 × 10^?6M, obtained from terbium (III) fluorescence titration with con-A. The dissociation constant of the complexes of con-A with other rare earth and transition metal ions was obtained through their competition with terbium (III) in the reaction with con-A, i. e. the quenching of con-A enhanced fluorescence. The results indicate that the binding of rare earth ions with con-A is dependent not only on their ionic radius but also on the hard-soft acid-base strength of the metal ions.     

两个新颖的1,10-菲罗啉衍生物的合成及其金属配合物在水溶液中热力学稳定性的研究

合成并表征了两个长链多齿配体2,9-二-(n-2′,5′,8′-三氮杂壬烷基)-1,10-菲罗啉(L1)和2,9-二-(n-4′,7′,10′-三氮杂十一烷基)-1,10-菲罗啉(L2). 研究了该配体及其与过渡金属离子和稀土金属离子配合物的热力学性质. 配体和金属离子的配位比都是1׃1. 对两个系列配合物的规律性及其差异以及对结果的影响因素也进行了研究. 结果表明, 所研究的稀土配合物都具有能催化水解生物大分子的11-1物种. 此性质表明它们是潜在的切割DNA和磷酸二酯水解酶的良好模型物.     

The effect of hydrolysed aluminium species in fluoride ion determinations

The limited ability of added ligands to mask the interference of Al(III) in fluoride determination by means of ion-selective electrode measurements has been re-examined, and an explanation based on competing equilibria developed. When the Al(III) level exceeds the fluoride content, the excess of A1(III) forms colloidal hydrous oxide particles in the pH range 4-9, and this solid strongly sorbs fluoride. Under these conditions, masking ligands have to promote both decomposition of AlF(x), soluble complexes and release of sorbed fluoride by substrate dissolution. The latter is a slow process, particularly with an "aged" gel, and long equilibration periods can be required for total fluoride release. Ion-chromatography studies have shown that the amount of fluoride lost through sorption on the hydrous oxide particles (isolated during the membrane filtration/degassing step) can be quite high. By analogy, preliminary phase separation of natural water samples must also separate sorbed fluoride and soluble fluoride complexes. In the presence of A1(III), accurate analysis for fluoride requires removal of the aluminium, or isolation of fluoride from the matrix, or very careful pretesting of masking efficiencies.     

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。     

掺杂稀土配合物的无机/高分子纳米杂化薄膜的 制备与发光性能

通过在溶胶-凝胶过程中引入高分子组分,并将稀土配合物掺杂其中的方法得到了具有良好发光性能的无机/高分子杂化薄膜,它们有很好的韧性和透明性,测定了薄膜的荧光光谱和荧光寿命,发现它们均发射出稀土离子的特征荧光且寿命比本体配合物增长。透射电镜的观察表明配合物在SiO~2/高分子互穿网络中分布较均匀,分散尺度在20～30nm之间。     

Local order around rare earth ions during the devitrification of oxyfluoride glasses

Erbium L(3)-edge extended x-ray absorption fine structure (EXAFS) measurements were performed on rare earth doped fluorosilicate and fluoroborate glasses and glass ceramics. The well known nucleating effects of erbium ions for the crystallization of cubic lead fluoride (based on x-ray diffraction measurements) and the fact that the rare earth ions are present in the crystalline phase (as indicated by Er(3+) emission spectra) seem in contradiction with the present EXAFS analysis, which indicates a lack of medium range structural ordering around the Er(3+) ions and suggests that the lead fluoride crystallization does not occur in the nearest neighbor distance of the rare earth ion. Molecular dynamics simulations of the devitrification process of a lead fluoride glass doped with Er(3+) ions were performed, and results indicate that Er(3+) ions lower the devitrification temperature of PbF(2), in good agreement with the experimental results. The genuine role of Er(3+) ions in the devitrification process of PbF(2) has been investigated. Although Er(3+) ions could indeed act as seeds for crystallization, as experiments suggest, molecular dynamics simulation results corroborate the experimental EXAFS observation that the devitrification does not occur at its nearest neighbor distance.     

稀土乙酰丙酮络合物的激光拉曼和红外光谱(Ⅰ)

本文测定了15个一水稀土乙酰丙酮络合物的激光拉曼和红外光谱,在401、415cm~(-1)附近的拉曼谱带对不同稀土离子表现敏感,它们随原子序数变化呈现“四分组”效应,这是第一次在振动光谱中观察到的镧系递变规律。该系列络合物的振动频率变化亦符合镧系“斜W”效应的规律,这些特征规律为确认401、415cm^-1附近谱带为M-O拉伸振动提供了最好的证据。实验结果同时可用于讨论M-O键的性质。     

Fabrication of fluorescent holographic micropatterns based on the rare earth complexes using azobenzene‐containing poly(aryl ether)s as macromolecular ligands

In this work, on the basis of photoinduced surface relief gratings (SRGs) with the rare earth complexes using azo‐polymers as macromolecular ligands, a series of novel materials for fabricating rewritable fluorescent two‐dimensional micropatterns, whose color can be easily adjusted by changing the species of the rare earth ions, are demonstrated. The rare earth complexes are prepared using a series of poly(aryl ether)s containing azobenzene chromophores and carboxyl group as macromolecular ligands and 1,10‐phenanthroline as co‐ligands. The fluorescence properties of the rare earth complexes and the influence of the contents of azobenzene chromophores on the fluorescent intensity are investigated by means of fluorescence excitation and emission spectroscopy. By exposing the films of the rare earth complexes to an interference pattern laser beam, SRGs can be formed on the films. Under the excitation, fluorescent patterns of the SRGs can be observed by the measurement of fluorescence microscopy. © 2015 Wiley Periodicals, Inc. J. Polym. Sci. Part A: Polym. Chem. 2015 , 53, 936–943     

对—苯二甲酸邻菲罗啉铕镧配合物的红外光谱及荧光光谱研究

用对-苯二甲酸铵和邻菲罗啉与氯化铕和氯化镧在乙醇-水溶液中反应,合成了对-苯二甲酸邻菲罗啉铕镧异核稀土配合物,测定了配合物的C,H,N和稀土元素的含量、红外光谱、紫外光谱及荧光光谱,确定了配合物的组成。结果表明,羧基氧和邻菲罗啉氮原子均与稀土离子配位,桥联配体对-苯二甲酸根可有效的传送能量,不发光的镧离子对铕离子的发光有明显的增强作用。     

掺杂比例和光敏剂对上转换纳米材料性能的影响

以NaYF_4材料为基质的上转换纳米颗粒(UCNPs)是最早报道的、应用范围最广的上转换材料之一。掺杂了稀土离子的颗粒不但可以在不同激发条件下发射出不同波长和强度的荧光,而且可以与多种光敏分子搭配使用,通过荧光共振能量转移产生单线态氧,实现生物医学成像或诊疗方面的应用。但是其形貌和荧光性能均受制备方法和工艺条件的影响较大。本文通过水热法合成了两类掺杂不同稀土离子的十种NaYF_4 UCNPs,在保持掺杂离子的终浓度不变的条件下,探究离子类型与比例对纳米材料的结构和上转换发光性能的影响。在此基础上,探索了多种卟啉类光敏剂分子与NaYF_4 UCNPs发生能量转换及单线态氧的产生能力。本工作可为基于NaYF_4材料的上转换颗粒的规模化制备和工艺升级提供数据支撑和理论参考。     

Ge-132稀土配合物及其对单核苷酸磷酯键的催化水解作用

Ｇｅ－１３２是具有广泛生物活性的一元羧酸有机锗倍半氧化物的低聚物,分子中存在类似冠醚的Ｇｅ－Ｏ－Ｇｅ大环结构．因此,有人认为Ｇｅ－１３２的生物活性可能与这种大环结构与体内金属离子形成配合物有关［１］,但尚无直接的实验证据．因此,合成Ｇｅ－１３２稀土配...     

Ce4+与RE3+的氟化物绿色分离方法

我国拥有得天独厚的稀土资源 ,已探明的稀土资源 (按氧化物ＲＥＯ计 )占全球稀土总量 80 %。然而 ,我国的稀土工业仍未摆脱资源利用率低和污染严重的困境 ,稀土资源的优势效应仍没有凸显出来。因此 ,稀土生产的绿色化[1] 对作为ＷＴＯ新成员的我国意义十分重大。现行的稀土冶炼工艺包括由化学浸取、化学分离和化学纯化等一系列线性的非循环的化学反应。如硫酸复盐沉淀分离法是通过Ｎａ2 ＳＯ4 与ＲＥ2(ＳＯ4 ) 3形成复盐沉淀实现Ｃｅ4 +与ＲＥ3+的分离 ,然后加入ＦｅＳＯ4 还原Ｃｅ4 +为Ｃｅ3+,再形成复盐沉淀 ,使Ｃｅ3+脱离硫酸介质体系。…     

稀土-氨基多羧酸配合物的配位结构及变化规律I氨基三乙酸(nta)、乙二胺四乙酸(edta)和反式-1,2-环己二胺四乙酸(cydta)系列

本文综述了稀土金属离子与一系列氨基多羧酸配体(如nta(=氨基三乙酸),edta(=乙二胺四乙酸),cydta(=反式-1,2-环己二胺四乙酸),dtpa(=二乙三胺五乙酸)和ttha(=三乙四胺六乙酸)等)形成配合物的分子结构和晶体结构,发现了这些配合物的配位规律和结构变化,说明了稀土金属离子象其它过渡金属离子一样,与氨基多羧酸配体形成配合物的配位数和配位结构取决于稀土金属离子的离子半径,电子结构和配体形状以及配电离子等。     

Optical properties and aggregation behavior of environmentally friendly Lanthanum (III) acyl–alaninnate complexes

Rare earth organic complex materials have attracted tremendous attention for their intrinsic properties and promising practical applications. It is still a great challenge to realize the rare earth organic complex materials with excellent functional properties and diversified structural states. Here, the amino acid rare earth surfactant complexes of lanthanum octanoyl-alaninate (La(oct-ala)₃), lanthanum octanyl-serinate (La(ser-oct)₃) and lanthanum octanoyl-phenylalaninate (La(oct-phe)₃) were synthesized by the reaction of C₁₁H₂₁NO₃, C₁₁H₂₁NO₄, C₁₇H₂₆NO₃ with LaCl₃, respectively. As-synthesized complexes of La(oct-ala)₃ and La(oct-phe)₃ have high solubility in pure solvent, while the solubility of La(ser-oct)₃ is very low in pure solvent. When the concentration of the complex solution is lower than the critical micelle concentration, the dissociation phenomenon of the complex is occurred in the solution. When the concentration of the complex solution is greater than the critical micelle concentration, the dissociated ligand ions and metal ions will associate, which can form micelle aggregates. In addition, the aggregates of the complex gradually shrink to form aggregates of different sizes and sizes as the solvent continues to volatilize. By further heating and cooling, the glassy, crystalline, liquid crystal and other complexes can be obtained. The rare earth organic low molecular complexes formed by the combination of these rare earth ions and amino acid ligands can not only obtain the complexes with high rare earth content, but also have the excellent properties of convenient synthesis, high yield, easy processing, good solubility, low toxicity and high stability, etc., which can play the special physical and chemical functional characteristics of the diversified structure state of rare earth organic molecular materials. Therefore, in present work, the lanthanum complexes as a functional molecular materials have potential applications in many fields.     

环烷酸类载体液膜体系对金属离子传输机理的研究

本文先在大块液膜体系中以环已烷甲酸为载体,通过正交设计,系统地研究了各种因素对希土离子输送作用的影响规律。比较了相同条件下RE~(3+)(希土)同Na~+,NH_4~+、Ca~(2+)和Fe~(3+)等离子的输送作用。发现在适当条件下,无皂化的羧酸载体对RE~(3+)离子具有良好的输送效果,同时证实,羧酸输送RE~(3+)离子是通过三个H~+离子与一个RE~(3+)离子的交换,而当载体皂化时,皂化的载体直接与接收相H~+离子发生交换,从而降低了羧酸对RE~(3+)离子的输送和分离效果。 在大块液膜研究的基础上,建立了一个以无皂化的环烷酸为载体的乳状液膜体系,从模拟离子矿的硫酸铵浸出液中萃取希土,通过正交试验确定了最优的液膜萃取条件,希土萃取率达96％以上,富集度30～40倍。     

稀土配合物的光致发光和电致发光研究

报道了稀土配合物在光致发光和电致发光的应用,从结构和性能的角度,分析了沁同稀土配合物的发光特性以及不同第一配体和第二配体对光致发光和电致发光的影响。     

稀土氨基酸配合物与核酸的相互作用*

很多抗癌金属药物是以核酸为靶标。阐明小分子与核酸之间的相互作用对筛选具有高效选择性和低毒副作用的抗癌药物有重要意义。近年来,开发新型的具有对核酸序列特异性识别能力的抗癌药物己成为本领域的研究热点。稀土离子具有良好的磁学、光学、电学特性和配位能力,使稀土配合物成为新型药物试剂。然而,稀土离子在中性条件下易水解的特性极大地阻碍了稀土配合物对核酸分子识别的研究。近年来在近生理条件下合成的一系列镧系氨基酸配合物具有结构稳定、溶解性好等优点,解决了镧系离子易水解的问题。本文总结了目前关于镧系氨基酸配合物与核酸的相互作用及其序列选择性等方面的研究进展。