Synthesis and Characterization of Rare Earth Nitrates Ternary Complexes with Glycine and 1,10-Phenanthroline

Eight new complexes with the general formula of RE(Gly)(NO_3)_3(phen)_2·3H_2O (RE=La, Ce, Pr, Nd, Gd, Sm, Er, Y) were synthesized and characterized by elemental analysis, molar conductivity, IR spectra, UV spectra and thermal analysis. All the complexes are stable in air and their conductance values in acetonitrile lie in the range of 204.1～239.4 S·cm2·mol -1, indicating 1∶2 type electrolytes. The IR shows that all the COO of glycine and oxygen atom of NO_3- take part in the coordination to the RE ions. The thermal behavior of La complex shows that the weight losses at 75～120 ℃ and 145～170 ℃ correspond to the loss of two lattice water molecules and one coordinated water molecules, respectively.

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(V)-SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 2,2'-DINITRO-4,5,4',5'-BIS-(15-CROWN-5)-DIBENZO DISULFIDE

Three new solid complexes of macrocyclic polyether ligand 2, 2'-dinitro-4, 5, 4', 5'bis-(15- crown-5)-dihenzo disulfide(L) with trivalent rare earth nitrates having composition of RE(NO_3)_3·L ·6H_2O(RE=Ce, Pr, Nd) have been synthesized in acetonitrile. All the isolated complexes have been characterized by elementary analysis, IR and UV spectra, differential thermal and thermogravimetric analysis, X-ray powder diffraction analysis, molar conductance and measurements of solubility in some general solvents.

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)with Uivalent 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 powder diffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows that coordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.

COMPLEXES OF RARE EARTH NITRATE WITH SCHIFF BASE DERIVED FROM VANILLIN AND P-TOLUIDINE

In this paper,complexes of rare earth nitrate with Schiff base derived from vanillin(3-methoxy-4-hydroxy-benzaldehyde)and p-toluidine[LnL_2(NO_3)_2]NO_3(Ln=La-Eu except Pm,L=Schiff base ligand) have been prepared and characterized.

Studies on Intermolecular Energy Transfer and Relaxation Processes in Solid Rare Earth Complexes by Photoacoustic Spectroscopy

The photoacoustic spectra of Eu ( benz)(3) (.) ( phen)(2) ( benz: benzoate, phen: phenanthroline) and Eu-0.(8)Ln(0.2)(benz)(3)(.)(phen)(2)(Ln(3+) : La3+ or Nd3+) were reported. The intermolecular energy transfer processes were studied from the point of the nonradiative transitions. Combined with the fluorescence spectroscopy, photoacoustic spectroscopy reflects the variation of the luminescence efficiencies of solid samples. The luminescence efficiency increases when La3+ is introduced, but it decreases greatly when Nd3+ is added, which is due to the difference of intermolecular energy transfer processes. The models of intramolecular and intermolecular energy transfer and relaxation processes were established.

Preparation and Characterization of Component Materials for Intermediate Temperature Solid Oxide Fuel Cell by Glycine-Nitrate Process

La1-xSrxGa1-y MgyO3-δ(LSGM) electrolyte, La1-xSrxCr1-y MnyO3-δ( LSCM ) anode and La1-xSrxFe1-y MnyO3-aaaaaaa(LSFM) cathode materials were all synthesized by glycine-nitrate process (GNP). The microstructure and characteristics of LSGM, LSCM and LSFM were tested via X-ray diffraction(XRD), scanning electron microcopy (SEM), A C impedance and four-probe direct current techniques. XRD shows that pure perovskite phase LSGM electrolyte and electrode (LSCM anode and LSFM cathode) materials were prepared after being sintered at 1400℃for 20 h and at 1000℃for 5 h, respectively. The max conductivities of LSGM (ionic conductivity), LSCM (total conductivity) and LSFM (total conductivity) materials are 0.02, 10, 16 S·cm-1 in the air below 850℃, respectively. The conductivity of LSCM becomes smaller when the atmosphere changes from air to pure hydrogen at the same temperature and it decreases with the temperature like metal. The porous and LSGM-based LSCM anode and LSFM cathode films were prepared by screen printing method, and the sintering temperatures for them were 1300 and 1250℃, respectively. LSGM and electrode (LSCM and LSFM) materials have good thermal and chemical compatibility.

Synthesis, Crystal Structure and Characterization of a One-dimensional Supramolecular Rare Earth Complex of N-(6-(4-Methylpyridinyl))ketoacetamide

A one-dimensional （1D） supramolecular rare earth complex [Nd（NO3）2L2-（C3H6O）][NdL（NO3）4]} （L=N-（6-（4-methylpyridinyl））ketoacetamide） has been prepared and characterized by elemental analysis, IR and electronic spectroscopy, and single-crystal X-ray diffraction. The crystal crystallizes in the triclinic system, space group P1^- with a=0.9146（6）, b=1.2581（8）, c=2.2316（14） nm, α=99.352（10）,β=97.209（9）, γ=103.935（9）°, V=2.422（3） nm3, Dc=1.776 g/cm^3, C33H42N12Nd2O25, Mr=1295.27, Z=2, F（000）=1288, μ=2.217 mm-1, R=0.0508and wR=0.1046 for 5173 observed reflections （I 〉 2σ（I））. In the structure of the title complex,one-dimensional supramolecular double-chains are formed by intermolecular hydrogen bonding interactions.

Catalytic Reduction of SO_2 on CeO_2-La_2O_3 Rare Earth Mixed Compounds

Adding rare earth oxide CeO_2 with variable valences to La_2O_3 formed a mixture of rare earth oxides. By means of dipping CeO_2, La_2O_3 and their mixture, whose carriers were all γ-Al_2O_3, were used as the catalyst for the reduction of SO_2 by CO. The activation process of this catalyst and the impact of temperature and reactant concentration on the activation process were investigated. Using X-ray diffraction, the structure characteristics of catalyst before and after reaction were analyzed to reveal the change of phase structure. The result shows that the rare earth oxide mixtures composing of CeO_2 and La_2O_3, as the catalyst for the reduction of SO_2 by CO, diminish activation temperature 50～100 ℃ less and have higher activity than a single oxide CeO_2 or La_2O_3. The reason possibl is that La_2O_3 goes into in the lattice of CeO_2 to form solid phase complex CeO_2-La_2O_3 and increases the capability of CeO_2-La_2O_3/γ-Al_2O_3 catalyst to store oxygen, which supplies the redox of CeO_2 reaction with a better condition. At the same time, elemental sulfur formed in the redox reaction impels La_2O_3 to be transformed to activation phase La_2O_2S in a lower temperature, which can be explained with the synergism between redox reaction and COS intermediate mechanism reaction.

Effect of Complexants on Nano-La_2O_3 Prepared by Solid State Chemical Reaction

Precursors were prepared by solid state chemical reaction between LaCl_3 and C_2H_2O_4·2H_2O or NH_4HCO_3 at ambient temperature. Differential temperature analysis (DTA) and thermogravimetric analysis (TGA) were used to determine the decomposing temperature. Oxide (La_2O_3) was obtained by decomposing the precursor for about 2.5 h. X-ray diffraction (XRD), scanning electronic microscope (SEM) and ZETA potentiometer were respectively used to analyze the composition, morphology and size distribution of the products. The results show that La_2O_3 prepared by LaCl_3 and C_2H_2O_4·2H_2O is of ball-like shape and the diameter of particles (95%) is below 50 nm, while La_2O_3 prepared by LaCl_3 and NH_4HCO_3 is net-like.

Preparation and Study of YSZ Electrolyte Doped with Multi-Elements by Combustion Synthesis with Glycin

Yttria stabilized zirconia (YSZ) is a kind of electrolyte materials widely used for solid oxide fuel cell (SOFC). Some rare earth elements (Dy 3+, Yb 3+, Sc 3+, etc), which have similar radii to Zr 4+, can dissolve into ZrO_2, and result in oxygen vacancy and crystal lattice distortion, so enhance its conductivity and lower the activation energy. YSZ electrolyte doped with Sc 3+(Dy 3+) and Yb 3+ were prepared by combustion synthesis. The conductivity is enhanced due to the distortions of crystal lattice and the increase in oxygen transfer passage radii, reaching 0.15 S·cm -1 at 1000 ℃. Crystalline symmetry of ZrO_2 changed from monoclinic to tetragonal, and then to cubic, with the elevation of calcining temperature. SEM photographs show the complex additives promoted growth of ZrO_2. There are some second phases along the grain boundaries, which restricted the further increase of conductivity. The addition of Al 3+ or Ca 2+ improve grain boundary, but lower the high-temperature conductivity.

Electrical Property of La_(0.7)Sr_(0.3)Cr_(0.5-y)Mn_(0.5-z)Co_((y+z))O_(3±δ) as Anode of SOFC

La0.7Sr0.3Cr0.5Mn0.4Co0.1O3±δ anode material was synthesized by glycine nitrate process. X-ray diffraction patterns indicate that single perovskite phase was created after sintering the predecessor at 1623 K for 5 h. By means of four-probe direct current, the electrical conductivities of La0.7Sr0.3Cr0.5Mn0.4Co0.1O3±δ were tested in different atmospheres, the maximum values were 10.2 S·cm-1 in air, 4.5 S·cm-1 in CH4 and 0.42 S·cm-1 in H2 at 1073 K, respectively. The compatibility between La0.7Sr0.3Cr0.5Mn0.4Co0.1O3±δ and La0.9Sr0.1Ga0.8Mg0.2O3-δ were investigated via X-ray diffraction and scanning electron microscopy, which shows that La0.7Sr0.3Cr0.5Mn0.4Co0.1O3±δ oxide, has good chemical and thermal compatibility with La0.9Sr0.1Ga0.8Mg0.2O3-δ. An electrolyte supported single cell consisted of La0.7Sr0.3Cr0.5Mn0.4Co0.1O3±δ|La0.9Sr0.1Ga0.8Mg0.2O3-δ|La0.9Sr0.1Ca0.1Fe0.8Co0.2O3±δ was fabricated through screen printing method. The open circuit voltage of the cell is about 0.92 V, and the maximum power density is about 75 mW·cm-2 at 1123 K.

Chemical equilibrium constants of rare earth nitrates and tri-n-butyl phosphate complex formation

Mixed rare earth nitrates （REi（NO3）3） in the aqueous solution was mixed with tri-n-butyl phosphate （TBP, （n-C4H9O）3PO） dissolved in kerosene for the formation of their corresponding complexes （REi（NO3）3·ni（n-C4H9O）3PO） at 303 K. The effects of initial concentrations of both TBP and mixed rare earth nitrates on the equilibrium constants of their complex formations were investigated. The complexes were formed almost immediately after mixing. The simultaneous formations reached their chemical equilibria within a few minutes by shaking the mixture at 200 r/min. The chemical equilibrium constants of the complex formations were independent of the initial TBP concentrations. However, they were decreased by reducing the concentration of REi（NO3）3. All equilibrium constants of the simultaneous complex formations were less than 0.7, while the average molar ratio of TBP to REi（NO3）3 of the complexes varied between 1.0 and 1.6. The chemical equilibrium constant for the formation of La（NO3）3·（n-C4H9O）3PO was 0.09, while that of Dy（NO3）3·（n-C4H9O）3PO was 0.68. The ascending sequence of chemical equilibrium constants for the simultaneous formations was La, Ce, Pr, Nd, Eu, Y, Sm, Gd, and Dy.

N,N′,N″-(三吡啶甲酰)-三乙氨基胺与稀土硝酸盐配合物的合成、表征与荧光性质

合成了三脚架型配体N,N′,N″ (三吡啶甲酰) 三乙氨基胺(L)及其稀土硝酸盐配合物,并通过元素分析、红外光谱、核磁共振与热分析谱对它们进行表征,同时,初步研究了配体及其Eu(Ⅲ)、Tb(Ⅲ)配合物在甲醇溶液的荧光性质。

硝酸稀土蛋氨酸固态配合物的热化学性质

用转动弹热量计测定了组成为ＲＥ（Ｍｅｔ）４（ＮＯ３）３·６Ｈ２Ｏ（ＲＥ＝Ｌａ～Ｎｄ，Ｓｍ～Ｌｕ）的固态配合物的燃烧能，求得了各配合物的标准燃烧焓与标准生成焓。发现标准生成焓随镧系元素原子序数的变化呈“四分组”规律，说明稀土离子与蛋氨酸间的化学键有一定程度的共价性。

La、Nd、Sm、Tb与HDBM配合物的固相反应合成与表征

研究了ＨＤＢＭ与Ｌａ、Ｎｄ、Ｓｍ、Ｔｂ等希土离子的固相配位反应，ＲＥＡｃ３·ｘＨ２Ｏ（Ｌａ、Ｎｄ：ｘ＝３／２；Ｓｍ：ｘ＝２；Ｔｂ：ｘ＝４）与ＨＤＢＭ进行固相配位反应制备ＲＥ（ＤＢＭ）３配合物，经元素分析、红外、Ｘ衍射和光声光谱检测进行表征。

杯[8]芳烃-硝酸稀土配合物的红外光谱及荧光性能

合成了以对叔丁基杯[8]芳烃(LH8)、硝酸根及DMF为配体,单一稀土RE3+(Sm3+、Eu3+、Tb3+、Dy3+)及混合稀土Tb3+∶Ln3+(Ln=La3+,Gd3+,Y3+)为中心的7种稀土配合物,对其进行了元素分析、摩尔电导、热谱、红外光谱及荧光性能研究。荧光光谱的测试表明所有Tb3+及其共掺杂配合物具有较强的特征荧光发射,荧光惰性离子La3+、Gd3+、Y3+对Tb3+的荧光有增强作用,其中Y3+的荧光增强作用最大,Gd3+次之,La3+最小。

镧系与直链醚-组氨酸Schiff碱新配合物的合成、波谱与生物活性

合成了直链醚 -组氨酸 Schiff碱 (四甘醇醛缩双组氨酸 Schiff碱 )及其稀土配合物 ,以元素分析、红外光谱、热重、磁化率等确定配合物组成为 Ln3( H2 L) 2 ( NO3) 9( Ln=La,Nd,Gd,Er,Yb;L=C2 0 H2 6 N6 O7) .采用交叉极化结合魔角旋转技术 ( CP/ MAS)和消除旋转边带技术 ( TOSS) ,获得固体高分辨 1 3 C NMR谱 ,见到— COO- 的 1 3 C谱峰分裂等新信息 .结合液体 1 H NMR谱等 ,对 L -组氨酸中咪唑基的配位进行了研究 .以EPR波谱探讨了配合物的晶体场强等特性 .观察到 Er配合物对超氧阴离子自由基的清除有一定效果 .

纳米YVO_4:Ln(Ln=Eu,Tm,Dy)发光粉的研制及与相应块体发光粉的光谱对比

采用络合溶胶—凝胶法合成出3种YVO4∶Ln(Ln=Eu,Tm,Dy)纳米发光粉,并且对纳米YVO4∶Ln与自合成的块体YVO4∶Ln的红外光谱(FTIR),荧光光谱和X-射线衍射以及粒径的分布进行了对比研究。实验结果证明,当钒基稀土发光材料粒径达到纳米级以后,由于纳米粒子的一些特性,导致发光材料的光谱与块体材料相比有了较大的不同,出现了不同程度的蓝移现象。并且纳米发光材料的发光强度较块体发光材料的强度有一定程度的增强。

Y_2O_3:Eu纳米晶的硝基取代苯甲酸配合物固相热解制备和性能

以苯甲酸、邻硝基苯甲酸、间硝基苯甲酸、对硝基苯甲酸、3,5-二硝基苯甲酸等为配体制备了Y3+、Eu3+二元配合物,配合物中Y3+与Eu3+的摩尔比为9:1.利用这些配合物的爆炸式热分解特性通过固相热解反应制备了一系列Y2O3:Eu纳米晶.透射电镜观察,可以看出所得纳米晶呈球形,粒度介于40～60nm,X射线衍射分析表明实验所得纳米晶属立方晶系,粒径与电镜观察所得结果基本一致;Eu3+的引入并不影响Y2O3的晶相组成;配体类型对纳米晶的结构没有显著影响,不过相对于硝基取代苯甲酸配合物,苯甲酸配合物热解所得Y2O3∶Eu纳米晶团聚严重;退火温度显著影响纳米晶粒度,退火温度高,纳米晶粒度大,反之亦然.荧光光谱测定表明所有Y2O3∶Eu纳米晶具有相似的发光行为,其中以苯甲酸配合物分解所得Y2O3:Eu纳米晶发光性能最为优越.

稀土甘氨酸配合物的制备及表征

在水溶液体系中合成了镧、钕、镝三种稀土硝酸盐与甘氨酸的固态配合物.采用元素分析、热分析和X-射线能谱分析、用傅立叶变换红外光谱仪(FT-IR)及全自动X射线衍射仪(XRD)对配合物进行了表征,确定了配合物的化学组成分别为La(NO3)3·(Gly)3·H2O,Nd(NO3)3·(Gly)3·H2O和Dy(NO3)3·(Gly)3·H2O.