SYNTHESIS AND CHARACTERIZATION OF RARE EARTH METAL COMPLEXES WITH PIPERONAL ISONICOTINOYL HYDRAZONE

Complexes of La(Ⅲ),Nd(Ⅲ),Sm(Ⅲ),Eu(Ⅲ),Gd(Ⅲ),Dy(Ⅲ), Er(Ⅲ),Yb(Ⅲ)and Y(Ⅲ)with piperonal isonicotinoyl hydrazone(HPIN) have been synthesized in DMF and EtOH.The complexes have been characte- rized by elemental analysis,molar conductance,i.r.,UV and^1H n.m.r. spectra,magnetic measurements,X-ray powder diffraction and DTA.

Study on Adsorption Behavior of Rare Earth Complexes on Nanometer-Size Titanium Dioxide with ICP-AES

A new method of using nanometer TiO 2 as solid phase extractant coupled with ICP AES was proposed for speciation of rare earth elements. The adsorption behavior of rare earth complexes on nanometer TiO 2 was investigated. Effect of pH value, contact time, elution solution and interfering ions on the recovery of the rare earth complexes were studied. A quantitative recovery (>90%) was found in the pH range of 4～9.0 for Eu citric, 4.5～9.0 for Eu oxine and Eu HIBA, and 6.5～9.0 for Eu 3+ . Eu EDTA can not be adsorbed in the pH range studied. There is large difference in the adsorption behavior on nanometer TiO 2 between rare earth element and its complexes. The possibility of application of nanometer TiO 2 on the speciation of rare earth element was explored.

Synthesis, Characterization of α-Oxopentanedioic Acid-Isonicotinoyl (Hydrazone) Rare Earth-Complexes and Relaxivity of Gd-complex

Oxopentanedioic acid isonicotinoyl hydrazone (H_2L) and its five rare earth complexes were synthesized with a view to further investigating MRI activities of the polycarboxylic Schiff base complexes. The complexes were characterized on the basis of elemental analyses, IR, UV, (()~1H) NMR spectra and thermal analyses. The general formula of the complexes is [Ln(HL)(H_2O)_2]Cl_2·H_2O (where Ln(Ⅲ)=La, Pr, Nd, Eu and Gd). In addition, the relaxivity ( R _1) of the Gd-complex was determined by INVREC Au program.

Effect of Complex Agents on Structure and Activity of Fe-Substituted Rare Earth Hexaaluminate Catalysts for Methane Combustion

A series of catalysts were prepared by using complex sol-gel methods.Experimental results confirm the effect of different agents on structure and activity of Fe-substituted rare earth hexaaluminate catalyst (LaFeAl11 O19 ) for methane combustion.The catalyst is yielded by complex sol-gel, respectively using three different complex agents (maltose, glucose and citric acid).XRD demonstrated that haxaaluminate is the major phase of catalyst prepared by maltose,while LaAlO3 is the major one of the catalyst by glucose and citric acid.At the same time, there is a little LaFeO3 and surface areas as well as 29.5 nm particle diameter when the complex agent is maltose.However, T10 ( temperature for 10% conversion of methane) and T100 ( temperature for 100% conversion of methane) for catalyst by glucose is 543 and 758 ℃, which is the best among the three complex agents for methane combustion.

Kinetics of Formation of Large-Dimension Rare Earth Inclusion in Steels

The elemental distribution within the large-dimension rare earth inclusion in steels was studied through analysis on plane distribution of elements by EPMA (Electron Probe Microanalyzer). The kinetics and mechanism of formation of RE inclusion were discussed, taking 5CrNiMo steel with the addition of RE and other microalloying elements as example. RE inclusions nucleate on oxides and sulphides with high melting point and grow up separately, then integrated by relatively high surface activity, which is a particular characteristic of RE elements, in liquid phase and during the course of solidification. Finally, the fine and dispersed RE inclusions merge and grow into a large-dimension one.

Structure and Bonding in Some Gd(Ⅲ) Metal Complexes Studied by Three-Dimensional X-Ray Analysis and ^(155)Gd Mssbauer Spectroscopy

Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the structure and bonding in lanthanide and actinide metal complexes using 166Er, t55Gd, and 237Np Mtissbauer spectroscopies in connection with single-crystal and/or powder X-ray diffraction, making clear the differences on their structures as well as the differences in the participation of 4f and 5f orbitals in the chemical bonds. In this article, the crystal structures of two novel Gd（Ⅲ） acetylacetonato complexes, Gd（pta）3 · 2H2O （pta = 1,1,1 -trifluoro-5,5-dimethy 1-2,4-hexanedione） and Gd（bfa）3 · 2H2O （bfa = 1, 1, 1 -trifluoro-4-phenyl-2-4-butanedione） were reported. Though both of them were dihydrate and had distorted square antiprismatical structure, Gd（pta）3 · 2H2O crystallizes in the P 2 1/n （#14） monoclinic space group and its lattice parameters are a = 1.4141（6） nm, b = 1.0708（3） nm, c =2.2344（4） nm, β =952.4（2）°, and Gd（bfa）3· 2H2O crystallizes in P 212121 orthorhombic space group and its lattice parameters were a = 1.322 （1） nm, b = 2.295 （1） nm, c = 1. 0786（8） nm. In the meantime, the authors had finished a systematic investigation on the ^155Gd Mossbauer isomer shift （δ） of various Gd（Ⅲ） metal complexes having a different coordination number （C.N.） and different ratios coordinating oxygen to nitrogen. A tendency for the 6 value to decrease with an increase in the C.N, and the number of the nitrogen atom coordinating to Gd was confirmed. This indicated that the Gd-O and/or Gd-N bond in the investigated Gd（Ⅲ） metal complexes had a small covalent contribution, which was possible to be deduced from the O and/or N atoms of the lisands donating electrons to 6s, 5d, and 4f orbitals of Gd.

稀土金属镥配合物有机电致发光器件性能研究

稀土元素因其独特的电子结构和丰富的跃迁能级备受关注。利用真空气相沉积法以稀土金属镥配合物Lu(DBM)_(3)Pyphen为发光层,m-MTDATA为空穴注入层,TPD为空穴传输层,制备了结构为ITO/m-MTDATA/TPD/TPD:Lu(DBM)_(3)Pyphen/Lu(DBM)_(3)Pyphen/LiF/Al的有机电致发光器件。最大亮度和电流效率分别为911 cd/m^(2)和1.1 cd/A,随着电压增加色坐标由(0.485,0.479)移动到(0.391,0.533)。器件发光颜色变化具有明显的电压依赖性,为可视信息存储提供了新的思路。

Synthesis of Heterometallic Rare Earth(Ⅲ)-Cobalt(Ⅱ)Complexes and Their Application in Alternating Copolymerization of Cyclohexene Oxide and Carbon Dioxide

Comprehensive Summary Four heterometallic rare earth(Ⅲ)-cobalt(Ⅱ)complexes(rare earth=Y(1),Sm(2),Nd(3),La(4))stabilized by an o-phenylenediamine-bridged tris(phenolato)ligand(L)have been synthesized and characterized.In these tetranuclear complexes,one polydentate L coordinates to one rare earth(Ⅲ)ion,and one cobalt(Ⅱ)ion,respectively,while two rare earth ions are bridged by four acetate groups.These complexes were applied in the copolymerization of cyclohexene oxide and CO_(2),which showed good activity(TON up to 440)and high poly(cyclohexene carbonate)selectivity(>99%).Kinetic studies determined the equation as rate=k[CHO]1[CO_(2)]0[initiator]1,which proves a first-order dependence on initiator concentrations and implies a synergistic mechanism with rare earth and cobalt ions cooperating in epoxide ring-opening and chain propagation.

Syndiotactic Polymerization of Styrene and Copolymerization with Ethylene Catalyzed by Chiral Half-sandwich Rare-earth Metal Dialkyl Complexes

The syndiotactic polymerization of styrene（St） and the copolymerization of St with ethylene（E） were carried out by using a series of chiral half-sandwich rare-earth metal dialkyl complexes（Cp^x＊） as the catalysts. The complexes are Ln（CH2SiMe3）2（THF）（1-4： Ln = Sc（1）, Ln = Lu（2）, Ln = Y（3）, Ln = Dy（4）） bearing chiral cyclopentadienyl ligand containing bulky cylcohexane derivatives in the presence of activator and AliBu3. For the St polymerization, a high activity up to 3.1 × 10^6 g of polymer mol Ln^-1·h^-1 and a high syndiotactic selectivity more than 99% were achieved. The resulting syndiotactic polystyrenes（sPSs） have the molecular weights（Mn） ranging from 3700 g·mol^-1 to 6400 g·mol^-1 and the molecular weight distributions（Mw/Mn） from 1.40 to 5.03. As for the copolymerization of St and E, the activity was up to 2.4 × 10^6 g of copolymer mol Sc^-1·h^-1·MPa^-1, giving random St-E copolymers containing syndiotactic polystyrene sequences with different St content in the range of 15 mol%-58 mol%. These results demonstrate that the bulky cyclopentadienyl ligands of the chiral half-sandwich rare-earth metal complexes effectively inhibit the continued insertion of St monomers into the（co）polymer chain to some extent in comparison with the known half-sandwich rare-earth metal complexes.

东昆仑大格勒地区稀有和稀土矿化碱性杂岩体的发现及意义

稀有、稀土元素由于其特殊的属性对国民经济、国家安全和科技发展具有重要的战略意义。与碱性岩类相关的稀有、稀土矿产资源储量十分丰富,近年来对其勘探和开发越来越受到重视。青海省地质调查院在东昆仑中段大格勒地区首次发现了稀有和稀土矿化碱性杂岩体,岩石类型主要为含尖晶石磷灰石蛇纹石化橄榄岩、含磷灰石金云母霞石单斜辉石岩、橄榄辉长岩、含磷灰石金云母角闪石岩、磁铁矿化含橄榄石磷灰石碳酸岩等,其中含矿岩石为碳酸岩、橄榄岩、辉石岩等。矿石矿物主要为烧绿石、铌钽铁矿、磷灰石、独居石、钛铁矿。现初步圈定Nb、P矿体一条,矿体厚3.8~56.56 m,Nb_(2)O_(5)品位最高6.9%,平均0.71%;P_(2)O_(5)品位最高14.5%,平均品位5.6%,Ta和REE也伴有矿化,显示了很好的含矿性。这一发现大大拓展了青藏高原稀有、稀土矿的找矿空间,为发现新的、优质的稀有稀土矿产提供重要启示,具有重要的找矿和战略意义。

SYNTHESIS AND CHARACTERISTICS OF HOMOBINUCLEAR MACROCYCLIC COMPLEXES OF RARE EARTH METAL ISOTHIOCYANATE AND PHENOLIC SCHIFF BASES

Eleven homobinuclear macrocyclic rare earth metal ions complexes are obtained as com-pounds of 2:2 Schiff base formed by condensing 2,6-diformyl-4-tert-Butylphenol and triethy-lenetetramine by a template procedure using rare earth metal isothiocyanates. These complexesare characterized by elemental analyses, FABMS, IR, conductivity and magnetic susceptibility.The variable-temperature magnetic susceptibility (4--300K) of complexes of Gd(Ⅲ) and Tb(Ⅲ) has been determined. A satisfactory fit to theoretical curve derived from spin Hamil-tonian operator was obtained by least squares method. The exchange interaction parameters areJ =-0.220 cm^(-1) for Gd, ,ZJ~?=-0.052 cm^(-1) for Tb. The results indicate a very weak anti-ferromagnetic interaction between Gd^(3+)-Gd^(3+), Tb^(3+)-Tb^(3+) ions.

NMR and IR Investigations of Ternary Inclusion Complexes among β-Cyclodextrin, Rare Earth Metal Ions, and Naphthalenediamines

Ternary inclusion complexes β-cyclodextrin （β-CD）, rare earth metal ions （YbC13, YC13）, and 1,8-naphthalene- diamine/ 1,5-naphthalenediamine are synthesized in basic aqueous media, which are characterized via IH NMR and IR spectroscopy. The stoichiometric proportion of β-CD ： YbC13 ： 1, 5-naphthalenedia- mine is 2：1：2, that of β-CD：YCI3 ： 1,8-naphthalenediamine is 2：1：1, and that of β-CD：YbC13 ： 1,8-naphthalenediamine is 2 ： 1 ： 1. The IR spectroscopy of the ternary inclusion complexes in the range of 935-1 000 cm 1 reveals the existence of the coordinate bond M---O or M---N. The possible conformations of the ternary inclusion complexes are depicted.

硫酸镁和硫酸铵浸矿对离子吸附型稀土与重金属的释放与影响机理

传统的硫酸铵与新型的硫酸镁是目前离子吸附型稀土矿原位浸矿主要的浸矿剂,除了关注稀土的浸取效率,稀土浸取过程中是否会引起伴生重金属的释出而对地下水环境造成影响是值得关注的问题。为此,以江西龙南稀土矿为研究对象,对比研究硫酸镁和硫酸铵浸矿剂条件下,pH、固液比及浸矿剂浓度对稀土及Pb、Mn、Cd等金属离子释放与变化的影响。结果表明:稀土浸出率和重金属受pH影响较大,其次是固液比和浸矿剂浓度。pH对浸出液中金属释放影响程度从大到小为:Pb>Mn>Cd。根据微观表征,浸出前后稀土矿中的主要矿物相组成未发生明显变化,高岭石、钾长石等矿相表面的Mn、Fe等重金属通过离子交换作用进入浸出液。整体上,硫酸铵较硫酸镁对RE 3+的释放迁移影响更显著,可能加剧重金属离子的释放,造成地下水中重金属的超标。

Solvent extraction and separation of light rare earth elements (La, Pr and Nd) in the presence of lactic acid as a complexing agent by Cyanex 272 in kerosene and the effect of citric acid,acetic acid and Titriplex Ⅲ as auxiliary agents

At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La（Ⅲ）,Pr（Ⅲ）, and Nd（Ⅲ） from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid（HLac） and auxiliary agents citric acid（H3 Cit）, acetic acid（HAc）, and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.

Synthesis, spectral, optical and anti-inflammatory activity of complexes derived from 2-aminobenzohydrazide with some rare earths

Three new metal complexes derived from Er（Ⅲ）, Dy（Ⅲ） and Zr（Ⅳ） with 2-aminobenzohydrazide （ABH） were synthesized and characterized by elemental analyses, IR, ^1H-NMR, ES-MS and transmission electron microscopy （TEM）. The morphology and the particle size were determined by TEM. The results showed that the ligand acted as neutral bi-dentate coordinating to the metal ions through the carbonyl oxygen and amidic amino nitrogen. The aromatic amine group remained inert towards coordination. The optical band gap was measured and found to be 3.3, 3.5 and 4.3 eV for Er（Ⅲ）, Dy（Ⅲ） and Zr（Ⅳ）, respectively. The optical band gap values indicated a semi-conducting nature of the investigated complexes. The anti-inflammatory and analgesic activities of the tested compounds were determined and compared with standard meloxicam.

Synthesis of Benzoxazine Functionalized Amine-Bridged Bis(phenolato) Rare Earth Complexes and Their Application in Ring-Opening Polymerization of rac-Lactide

The reactivities of benzoxazine functionalized amine bridged bis(phenol)s LnH_(2)(n=1—3)with rare earth metal complexes were explored,founding that both the aryl substituents of the ligand and the rare earth metals have profound influences on reaction outcomes.

富含间规聚苯乙烯链段的乙烯/苯乙烯共聚物的合成及力学性能

文中采用半夹芯型稀土金属配合物催化乙烯和苯乙烯共聚,合成了一系列具有不同共聚单体组成、富含间规聚苯乙烯链段的乙烯/苯乙烯共聚物。通过控制苯乙烯的投入量调控共聚物中乙烯的插入率,研究了乙烯插入率对共聚物熔点和力学性能的影响。结果表明,当乙烯插入率从9.6%升高到27.6%,共聚物中间规苯乙烯连续链段变短,熔点从256.3℃逐渐降低至241.4℃;当乙烯摩尔分数为72.9%时,表现出类似乙烯的熔点126.3℃。随着乙烯插入率的升高,材料的拉伸强度、弯曲强度逐渐降低,断裂伸长率、冲击强度逐渐升高,将乙烯插入间规聚苯乙烯链段有效改善了材料的脆性。当共聚物中乙烯摩尔分数为22.0%时,拉伸强度和冲击强度分别为54.3 MPa和20.4 kJ/m^(2)。文中合成的乙烯/苯乙烯共聚物强度大、熔点高,并具有一定的韧性。

硫醚与2-甲基-1,5-己二烯反应的机理研究

采用密度泛函理论对硫醚与2-甲基-1,5-己二烯的反应机理进行了详细的理论探究.计算结果表明,该反应历程主要包含活性物种的生成、2-甲基-1,5-己二烯的插入、另一分子的硫醚的碳氢键活化三部分.在2-甲基-1,5-己二烯插入步骤中,发现其采用6-5-re-插入时需要克服的活化能垒最低,反应时更为占优,在进行烯烃分子内碳碳双键插入完成闭环反应时相对比较容易.通过能量对比探明硫醚的C-H键活化需要克服的能垒最高,为该反应的速控步.

Combination of on-line preconcentration by di(2-ethylhexyl) phosphoric acid resin in the presence of complexing agent with microwave plasma-atomic emission spectrometry for the determination of rare earths

The adsorption of rare earths,lanthanum,cerium,neodymium,and yttri um by di(2-ethylhexyl) phosphoric acid(D2EHPA) resin in the presence of a compl exing agent,EDTA,was investigated. Flow injection was selected as the injectin g method. Various parameters,sample pH,sample loading time,sample flow rate,EDTA concentration,EDTA flow rate,eluent concentration,and eluent flow rate,were studied and optimized. Under the optimum conditions,the method allowed the determination of rare earths with detection limits of 1.09 μg/L(lanthanum),3 .31 μg/L(cerium),2.05 μg/L(neodymium),and 1.25 μg/L(yttrium) . High repea tabilities were obtained for all the four rare earths(RSD【5%) . The proposed met hod was applied to the determination of the rare earths in water samples with a recovery range of 95.8%-103.3%.

Rare-earth dialkyl and dihydride complexes bearing monoanionic ancillary ligands

This paper gives a brief overview on recent progress in the chemistry of rare-earth dialkyl and dihydride complexes with monoanionic supporting ligands.The dialkyl complexes serve as excellent catalysts for the polymerization and copolymerization of a wide range of olefins to give novel polymer materials difficult to prepare by other means.The dihydride species show unique features in terms of both their structure and reactivity,which are in sharp contrast with those of the monohydride analogues bearing two supporting ligands.