Preparation and Characterization of Polymer－Supported Rare Earth Complexes

he polymers containing different ligand groups of atoms(mainly O,N,and S)and their rare earth complexes were prepared,characterized and classified based on the type of metal-ligand bonding. The catalytic activities of the complexes are briefly discussed.The polymer- supported rare earth complexes shwed much greater activities than the correspond- ing complexes with a low molecular weight.

CATALYTIC ACTIVITIES OF RARE-EARTH CALIXARENE COMPLEXES IN POLYMER SYNTHESES

The studies of our group on the catalytic activities of rare earth calixarene complexes in polymer syntheses are reviewed. Rare earth calixarene complexes are effect catalysts for the polymerizations of butadiene, isoprene, ethylene, styrene, propylene oxide, styrene oxide, trimethylene carbonate and 2,2-dimethyl-trimethylene carbonate.

RARE EARTH CONTAINING POLYMER TERNARY COMPLEXES AND THEIR FLUORESCENT PROPERTIES

Rare earth containing fluorescence active polymer ternary complexes were synthesized and their absorption and emission properties were investigated.

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.

POLYMER-SUPPORTED RARE EARTH CATALYSTS FOR STYRENE POLYMERIZATION

The neodymium complex supported on styrene-maleic anhydride copolymer (SMA·Nd) has been prepared for the first time and found to be a highly effective catalyst for the polymerization of styrene. The SMA·Nd polymeric complex is characterized by IR and its catalytic activity, and the polymerization features have been investigated in comparison with that of the conventional Ziegler-Natta catalysts. When [Nd]=1×10^(-3) mol/L, [M]=5mol/L, Al/Nd=170(mol ratio) and CCl_4/Nd=50(mol ratio), the polymerization conversion of styrene gets to 51.6% in six hours, and the catalytic activity reaches 1852 gPS/gNd, which is much higher than that of conventional rare earth catalysts. The polymerization reaction has an induction period and shows some characteristics of chain polymerization. The polymerization rate is the first order with respect to the concentration of styrene monomer. Addition of FeCl_3 does not suppress the polymerization.

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.

POLYMER SUPPORT EFFECTS OF METAL COMPLEXES FOR CATALYSIS

In the course of investigating the catalytic behavior of metal complexes for ring opening metathesis polymerization of cycloolefins, metathesis, hydroformylation and selective hydrogenation of olefins experimental results time and again indicate the presence of effects of macromolecular supports - the utilization of macromolecular supports increases obviously the activity, selectivity, and stability of the catalysts and so as to increase the conversion of substrates, yields of reactions, properties of formed polymers and so on. Discussed these effects on the basis of the authors' experiments. (Author abstract) 18 Refs.

Synthesis and Catalytic Activities of Polymer-Supported Neodymium Complexes——Polymers Containing Thiol and Sulphoxide

The neodymium complexes with crosslinked polystyrene containing -CH2SH and -CH2SOCH3 groups, P-CH2SH . NdCl3 and P-CH2SOCH3. NdCl3, were prepared. P-CH2SH . NdCl3 shows no catalytic activity for butadiene polymerization, while P-CH2SOCH3. NdCl3 can catalyze the polymerization of butadiene. The content of cis-1,4-polybutadiene is more than 95%.

Transport of yttrium metal ions through fibers supported liquid membrane solvent extraction

A novel idea of transport of yttrium(Ⅲ) metal ions through fibers supported liquid membrane in two stage processes namely source to membrane and membrane to receiving phase has been proposed.The fibers supported liquid membrane was impregnated with different concentrations carrier.The experimental variables explored were concentration of yttrium(Ⅲ) ions,pH of source phase,PC-88A concentration in membrane phase,acid concentration in receiving phase and stirring speed.The pre-concentration of yttrium(Ⅲ) ions ...

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.

Syntheses and Characterization of Two New Alkaline Earth Metal-organic Topological Frameworks with 3-Amino-1H-1,2,4-triazole-5-carboxylate

Two new alkaline earth metal coordination polymers constructed from the deriva-tive of 1,2,4-triazole are presented herein,namely,{[Sr（AmTAZAc）2（H2O）]}（1） and {[Ba（AmTAZAc）2（H2O）]}（2）（AmTAZAc = 3-amino-1H-1,2,4-triazole-5-carboxylate）,which have been synthesized by using the layering method and structurally characterized by elemental analysis,IR,and single-crystal X-ray diffraction.Complexes 1 and 2 are isostructural,and both crystallize in the orthorhombic system,space group Fdd2.X-ray structural analysis shows that 1 or 2 has an intriguing 3-D infinite network of（318.438.510） topology based on a 2-D sheet structure of（4,4） net.The result shows that noncovalent interactions play an important role in strengthening the whole structures of the compounds.

Preparation Physicochemical Characterization and Catalytic Applications of Polystyrene Ethylenediamine Tetra acetic Acid Cu(II) Metal Complex

Chloromethylated styrene-divinylbenzene copolymer beads with 8% crosslink were chemically modified by reaction with Ethylenediaminetetraaceticacid leading to the incorporation of nitrogen as ligating site on the surface of the polymer. The polymeric ligand on treatment with a solution of Copper chloride gave the corresponding metal complex. The polymer supported Cu(II) complex was characterized by elemental analyses, IR,GC-MS, scanning electron micrographs (SEM). The oxidation of various alcohols such as benzyl alcohol, 2-butanol, and 2-propanol was investigated using the supported metal complexes in presence of molecular oxygen as the oxidant. The swelling studies were done by using different solvents. Kinetic data indicate that the catalysts could be recycled without significant degradation of polymer matrix.

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.

Rare earth oxides and their supported noble metals in application of environmental catalysis

Volatile organic compounds(VOCs),methane,carbon monoxide,soot,automotive exhaust,and nitrogen oxides are harmful to the atmosphere and human health.It is urgent to strictly control their emissions.Heterogeneous catalysis is an effective pathway for the removal of these pollutants,and the critical issue is the development of novel and high-performance catalysts.In this review,we briefly summarize the preparation methods,physicochemical properties,catalytic activities,and related reaction mechanisms for the above pollutants removal of the rare earth oxides,mixed rare earth oxide,rare earth oxidesupported noble metal,and mixed rare earth oxide-supported noble metal catalysts that have been investigated by our group and other researchers.It was found that catalytic performance was associated with the factors,such as specific surface area,pore structure,particle size and dispersion,adsorbed oxygen species concentration,reducibility,reactant activation ability or interaction between metal nanoparticles and support.Furthermore,we also envision the development trend of such a topic in future work.

Hydrothermal synthesis and structural studies of a new coordination polymer of lanthanum(Ⅲ) with benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridine

A new lanthanum complex formulated as {（bpyH2）[La（btc）（H2O）4（NO3）]·2H2O}n （1） （btcH4=benzene-1,2,4,5-tetracarboxylic acid; bpy=4,4＇-bipyridine） was hydrothermally synthesized. The complex was characterized by FT-IR spectroscopy, elemental analysis and X-ray diffraction. X-ray crystal structural analysis revealed that the compound belonged to the monoclinic space group C2/c with cell parameters a= 1.42806（7） nm, b=1.10258（5） nm, c=1.60333（8） nm and β=101.9400（10）°. The complex was polymeric with La^III atoms linked by four O atoms from two carboxylate groups of one benzene-1,2,4,5-tetracarboxylate. The LaIn atom was ten coordinated in a distorted tetracapped trigonal prism. In the crystal structure, a wide range of noncovalent interactions consisting of hydrogen bonding （of the types of O-H…O, N-H…O and C-H…O） and ion pairing interactions connected the various components into a supramolecular structure.

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.

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.

Synthesis and Structures of Three Erbium(Ⅲ) Dicarboxylate Coordination Polymers

Three polymeric erbium(Ⅲ) complexes [Er(oba)(Hoba)(H 2O) 2]H 2O (A),[Er 2(oba) 3(H 2O) 4] (B), [Er 2(oba) 3(2,2′ bpy) 2] (C) (H 2oba=4,4′ oxybis(benzoic acid), 2,2′ bpy = 2,2′ bipyridine) were hydrothermally synthesized by altering the metal/carboxylate ratios or in the presence of an additional chelate 2,2′ bpy ligand, and characterized by single crystal X ray diffraction. The results show that different metal/carboxylate ratios can influence the polymeric structures and the presence of 2,2′ bpy ligand alters the topology of the framework from two dimensional to three dimensional.