Keggin结构稀土钼钒磷四元杂多配合物的合成、表征及苯酚羟化制苯二酚的催化活性

合成了5种通式为(NH₄)₁₅[RE(PMo₉V₂O₃₉)₂]·xH₂O(RE=La³⁺,Ce³⁺,Gd³⁺,Y³⁺,Yb³⁺)的稀土钼钒磷四元杂多配合物,并用IR,UV,XRD,ICP,TG-DTA和CV等手段对其结构和性能进行了表征.催化活性实验表明,标题化合物对苯酚过氧化氢羟化制苯二酚反应有良好的催化活性.     

稀土离子与硫氰酸根及硝酸根的络合作用

在25℃下,以2MNaClO₄维持水相的离子强度恒定,用离子交换法测定了除Ce和Pm以外的镧系元素及钇与CNS^-和NO₃^-的络合作用。用北京大学6912计算机处理了实验数据。结果表明:(1)RE³⁺与CNS^-的络合作用不大,当[CNS^-]≤1.5M时,主要以RECNS²⁺,RE(CNS)₂⁺及RE(CNS)₃三种络合物形式存在;镧系元素与CNS^-的络合度Y₍₁₎随原子序数Z的增大,总的趋向是增大,钇的Y₍₁₎值为最小。(2)RE²⁺与NO₂⁺的络合作用较弱,当[NO₂⁺]≤1.5M时,主要的络合物是RENO₃²⁺;各镧系元素与NO₃^-的Y₍₁₎随Z的增大,总的趋向是减小,钇的Y₍₁₎值最小。(3)在本实验中,稀土络合离子在树脂上的吸附量是可以忽略不计的。     

稀土硝酸盐冠醚配合物(ⅩⅥ)——冠醚B12C4与稀土硝酸盐配合物的合成与性质

在乙腈和丙酮中合成了冠醚B₁₂C₄与稀土硝酸盐的配合物RE(NO₃)·B₁₂C₄·xH₂O。通过金属离子的配位滴定、冠醚B₁₂C₄的分光光度测定、溶剂的气相色谱分析以及红外光谱、差热(DSC)与热重分析和X-射线衍射分析等方法研究了配合物的组成和性质。还在15±0.1℃测定了各配合物在乙腈中的溶解度。考察了重稀土(Tm、Yb和Lu)配合物1:1型向2:1型的转变。     

Preparation, thermal stability and luminescence properties of selected rare earth oxycarbonates

A comparative TG and DTG study of the preparation and thermal stability of selected rare earth oxycarbonates, (REO)₂CO₃ (RE = La and Gd), shows that the ease of formation as well as the stability of these compounds decreases strongly with increasing atomic number of the host cation. According to X-ray powder diffraction analyses, the RE oxycarbonates obtained as decomposition products of acetate and carbonate hydrates belong to the tetragonal IA-type. UV- and dye laser-excited luminescence studies of Eu³⁺-doped (LaO)₂CO₃ and (GdO)₂CO₃ reveal the presence of two different sites for the host cation. One of the sites resembles closely that prevailing in the tetragonal RE oxysalts, i.e. oxyhalides, oxysulphates, oxymolybdates and oxynitrates. A crystal field analysis carried out on the ⁷F₁ and ⁷F₂ level schemes according to a C_2v site symmetry confirms this hypothesis.     

2-苯基喹啉-4-甲酸稀土配合物的研究

制备了十五种稀土与2-苯基喹啉-4-甲酸的配合物,确定其组成为REA₃·2H₂O(RE=Y,La-Nd,Sm-Lu,A=C₁₆H₁₀NO₂^-);研究了IR、UV、H-NMR、分子荧光光谱、摩尔电导、溶解性及热稳定性等。     

尖吻蝮蛇毒抗凝血因子Ⅱ的稀土离子荧光探针研究

尖吻蝮蛇毒抗凝血因子(ACF)分子中有两个钙离子结合位点,钙离子对ACF的内源荧光有增强作用,稀土离子(Nd³⁺,Sm³⁺,Eu³⁺,Gd³⁺和Tb³⁺)能取代ACF分子中的钙离子,并对ACF的内源荧光有不同程度的猝灭作用,其中Tb³⁺接受ACF分子中Trp残基传递的能量后,特征荧光增强.稀土离子与ACF荧光滴定表明,ACF分子中有两个稀土离子结合位点,稀土离子和钙离子在ACF分子中两个结合部位是共同的竞争结合部位.ACF与不同稀土离子之间有相近的表观结合常数K₁或K₂.Tb³⁺与RE³⁺(RE=Nd,Sm,Eu或Gd)间线性自由能关系表明,稀土离子与ACF结合时,没有明显的空间效应.ACF分子中的两个结合位点在结构上都有较大的柔性,这种结构柔性为钙离子在ACF与活化凝血因子X的结合反应中起到的促进作用提供了结构基础.     

稀土气态配合物的热力学性质

稀土气态配合物的热力学性质王林山,王之昌（东北大学化学系,沈阳,１１０００６）关键词稀土气态配合物,热力学性质,钆断目前,对稀土液相和固相配合物已有了较为全面的研究,并总结出其热力学性质与原子序数或离子基态之间有钆断、四分组、斜Ｗ等实验规律或效应［１...     

CoFe2-xRExO4(RE=Tb,Dy)纳米晶薄膜的化学合成及磁性

以溶胶-凝胶法制备了稀土铽或镝掺杂的钴尖晶石铁氧体纳米晶薄膜.考察了Tb或Dy的掺杂量及晶化条件对晶相的影响.结果表明,稀土离子的掺杂量x超过0.3时,样品很难形成尖晶石单相.原子力显微镜对纳米晶薄膜表面形貌的观测显示,溶胶-凝胶法制备的薄膜粒度可控制在20～50nm,且具有较高的表面平整度.对于厚度为200nm的薄膜,均方根粗糙度仅为4～5nm.磁特性研究发现,掺杂Tb或Dy的样品矫顽力明显提高.     

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(Ⅳ)SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 4''''-BROMO-5''''-NITROBENZO-15-CROWN-5

Six new solid complexes of macrocyclic polyether ligand 4′-bromo-5′-nitrobenzo-15-crown-5(L)withUivalent rare earth nitrates having composition of RE(NO_3)_3·L·mCH_3CN·nH_2O(RE=L_a--Nd,m=n=0,RE=Sm,Bu,m=0.1,n=1,4)have been synthesized in acetonitrile or acetone.All the isolated complexes have been char-acterized by elementary analysis,IR and UV spectra,differential thermal and thermogravimetric analysis,X-ray powderdiffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows thatcoordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.     

杂环胺双齿配体萃取稀土元素

对一系列杂环双齿配体--4,7-二苯邻菲绕啉、5-硝基邻菲绕啉、2,9-二甲基邻菲绕啉、2,9-二甲基-4,7-二苯邻菲绕啉和α,α＇-联喹啉(以下均用L表示)与CCl₃COO-和15种正三价稀土离子形成的三元络合物在水-氯仿间的革取行为进行了研究。发现在这些体系中,都存在明显的“四分组效应”,且稀土的萃取率随介质pH而变化。井讨论了L的分子量及结构对稀土萃取的影响。     

KBr-RE(La,Sm)Br3-13%HBr-H2O四元体系25℃时的相平衡研究

Meyer在研究K。REBr。（RE一La,Sin）的结构及热力学性能时,引用文献的方法合成了2：1型化合物见s．其具体反应机理尚未明确表示．根据文觎',合成2：1型化合物CSZLUCI。分两步：第一步是LtJ;03与CSCI在氢氯酸介质中反应,生成2：1型含结晶水的中间体CS入llCI;·H20;第二步是中间体在HCI气氛下的高温脱水反应．反应如下：HC＊＊;HCI;＊ISOOC4CSCI＋l。LI,O。、ZCS,LSCI。·H,O、ZCS,LllCI。－H人）由上述反应过程可见,中间体的形成实际上应是LLICI。与CSCI在HCI介质中反应的生成物．那么,Meye…     

EIS Study on the Electrochemical Properties of RE(Ni,Co,Mn,Ti)s Alloys (RE=La,Ce,Pr,Nd) at Different Depths of Discharge (DOD)

In the present investigation, EIS was employed to study the electrode kinetics of AB₅ typed RE (Ni, Co, Mn, Ti)₅ alloy and compare the difference of rare earth component effects when pure La, Ce, Pr or Nd was used individually for RE in the alloy respectively.     

Synthesis, characterization and catalytic application of SBA-15 immobilized rare earth metal sandwiched polyoxometalates

Rare earth metal sandwiched Keggin-type heteropolyoxometalates, K₁₁[RE(PW₁₁O₃₉)₂] (RE–PW₁₁, RE = La, Ce, Pr, Nd, Sm, Eu, Dy and Y), were anchored onto aminosilylated mesoporous silica SBA-15 and the resulting RE–PW₁₁/APTS/SBA-15 materials were characterized by ICP, FT-IR, XRD, N₂ adsorption, ³¹P MAS NMR and TEM. The RE–PW₁₁ clusters preserve their structure in the surface-modified mesopores. The catalytic activity of RE–PW₁₁ clusters was tested on heterogeneous oxidation of cyclohexene by H₂O₂. The interaction between RE–PW₁₁ and amino groups grafted on the channel surface of SBA-15 leads to strong immobilization of RE–PW₁₁ due to the introduction of the rare earth metal centre, which is against the leaching during the reaction.     

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in “pure” rare earth matrices by inductively coupled plasma atomic emission spectrometry: Part VII — Terbium, Dysprosium, Holmium and Thulium

This article is the seventh part of a series of papers discussing the spectral interferences of rare earth elements (REEs) in ICP-AES. Radial viewing 27.12 MHz inductively coupled plasma atomic emission spectrometry (ICP-AES) was used in the determination of scandium, yttrium and rare earth elements in Tb₂O₃, Dy₂O₃, Ho₂O₃ and Tm₂O₃ as “pure” rare earth matrices. The quantification of the interferences in terms of Q-values for line interference Q_I(_a) and wing background interference Q_W(Δλ_a) were used in accordance with Boumans and Vrakking [Spectrochim. Acta Part B 43 (1988) 69]. The “best” analysis lines from point of view of spectral interferences were selected. The true detection limits by using the “best” analysis lines were calculated.     

Formation of stabilized zirconia with rare earth fluorides

New reactions to prepare stabilized zirconia using rare earth fluorides as the solid electrolyte have been examined by means of X-ray diffraction, DTA and EPMA methods. The eleven rare earth fluorides of yttrium and samarium through lutetium reacted with ZrO₂ to form new types of stabilized zirconias (LnFSZ) consisting of the ternary system of ZrO₂-Ln₂O₃-LnF₃. (2x+3y)ZrO₂ + (4y+2z)LnF₃ = 2(ZrO₂)_x(Ln₂O₃)_z + 3yZrF₄) where x, y and z represent the stabilizing composition at which the homogeneous solid solution with the fluorite structure is formed, and x + y + z + = 1. This reactions begins to take place at about 600 C and is completed by firing at temperatures ranging from 1000 to 1300 °C for a few hours in an argon atmosphere.     

二甲亚砜硝酸稀土晶体的生长及其组成与性质的研究

本文合成出除Pm以外的全部稀土硝酸盐的二甲亚砜晶体,并生长出大尺寸的La和Nd的晶体(分别为60×28×25和80×28×28mm)。从La至Gd的组成为RE(NO₃)₃·4DMSO,从Tb至Lu(包括Y)的组成为为RE(NO₃)₃·3DMSO,由于镧系收缩引起的空间位阻,使结合的DMSO的数目从4减为3。测定了一些稀土的光谱和发光性质。比较Nd³⁺在水溶液中和在DMSO中的吸收光谱,观察到在DMSO中Nd³⁺的谱带向长波位移,表明了在DMSO中,RE—O键具有一定程度的共价性。当晶体在850℃的空气中进行热分解时,三价稀土的热分解产物的组成为RE₂0₂SO₄。测定了全部稀土硝酸盐的二甲亚砜晶体的磁化率,它们随原子序的增大呈现具有双峰的周期性变化。     

喷雾热解制备稀土超细粉末(Ⅰ)——氧化钇粒子形态与形成机理

对Y(NO₃)₃·6H₂O的差热和热重分析表明,Y(NO₃)₃·6H₂O经脱水和热分解在580C以上完全分解为Y₂O₃.在此基础上,以Y(NO₃)₃·6H₂O为前驱体,采用喷雾热解过程制备出粒度为0.50～1.50μm的立方相球形Y₂O₃粉末.通过对产物粒子粒度的理论计算与实验结果的比较,推测Y₂O₃粒子形成机理符合液滴-粒子转变机理(One-Droplet-One-Particlemechanism).本喷雾热解过程同样适用于其它稀土超细粉末的制备,粒子粒度可以通过调节液滴尺寸和溶液浓度等操作条件进行控制.     

吡啶二羧酸修饰的稀土嵌入碲钨酸盐的合成及电化学生物识别性质

在乙酸钠水溶液中, 采用微波加热一步自组装策略合成了一系列罕见的2,6-吡啶二羧酸修饰的稀土嵌入Keggin型碲钨酸盐(PTEA)₇H₃K[RE₂(B-α-TeW₉O₃₃)₃W₃O₅(H₂O)₃(HDPA)]·22H₂O[RE=Ce³⁺(1), Pr³⁺(2), Nd³⁺(3), Sm³⁺(4); H₂DPA=2,6-吡啶二羧酸; PTEA=质子化的三乙醇胺]. 化合物1~4的聚阴离子由3个三缺位Keggin型 [B-α-TeW₉O₃₃]^8-构筑块通过1个{RE₂W₃O₅(H₂O)₃(HDPA)}¹³⁺异金属簇连接而成. 该异金属簇中, 2,6-吡啶二羧酸作为四齿配体与2个稀土离子(RE1和RE2)配位形成平面三杂环结构, 且RE1和RE2所在平面与W2, W2A, W16形成的平面互相垂直. 此外, 化合物1可与羧基化多壁碳纳米管(CMWCNT)复合形成1-CMWCNT复合材料. 该复合材料可以作为电极材料构建电化学生物传感器, 用于检测特定的DNA序列.     

The luminescence system of yttrium(III)-BPMPHD-CTMAB and the determination of yttrium(III)

The study indicated that yttrium(III) could form an ion association compound with a new synthetic reagent, 1,6-bi(1′-phenyl-3′-methyl-5′-pyrazolone-4′-)hexanedione (BPMPHD) and cetyl trimethyl ammonium bromide (CTMAB). The compound could enhance the natural fluorescence of BPMPHD by about 260 times, upon which a new fluorescence method was developed for determining yttrium in rare earth (RE) samples. The determination range was 9–900 ng/ml. The detection limit was 1.8 ng/ml. The composition of the ion association was [Y(BPMHD)₂]⁻CTMAB⁺.     

D-葡萄糖与氯化稀土配合物的合成及红外光谱研究

以非水溶剂为介质合成了D-葡萄糖、氯化稀土、吡啶的混配多元配合物,并进行了元素分析和红外光谱测定。研究结果表明,D-葡萄糖和溶剂吡啶同时参与了配位,该配合物的组成为:Ln(C₆H₁₂O₆)(C₅H₅N)Cl₃(Ln=La,Ce,Pr,Nd,Sm等).本文还对配合物的可能结构进行了讨论。