Studies on synthesis and fluorescent property of rare earth complexes RE(ABMF)_2AA and copolymers RE(ABMF)_2AA-co-MMA

Four new complexes RE（ABMF）2AA（RE=Sm, Eu, Tb, Dy） were synthesized by the reaction of RECl3·6H2O with acrylic acid（HAA） and 1-（2-furyl）-3-phenyl-1,3-propanedione（ABMF）.The copolymerization of the rare earth complexes with methyl methacrylate was studied by using 2,2-azobis-isobutyronitrile as an initiator.The composition and structure of the four complexes were characterized by elemental analysis, UV-vis and FTIR.The glass transition temperature and molecular weight of the copolymers were determined.Photolu-minescent measurement showed that ligand ABMF could efficiently transfer the energy to Sm^3＋ and Eu^3＋ ions in the complexes and sensitize the luminescence of the rare earth ions, but could not sensitize Tb^3＋ and Dy^3＋ ions.As a result, both Sm^3＋ and Eu^3＋ complexes emitted the characteristic fluorescence of Sm^3＋ and Eu3＋ ions due to the f-f transitions.The four copolymers could emit strong fluorescence of the rare earth ions.

Review on Rare Earth/Polymer Composite

The special properties of rare earth/polymer composite were described. More emphasis was put on the radiation shielding and magnetic properties. In the application to X-ray shielding, rare earth/polymer composite can make up the feeble absorbing area. If the rare earth content is high enough, it can demonstrate strong ability for thermal neutron absorption; The composite has strong paramagnetism. The feasibility of preparing magnetic rare earth/polymer composite was discussed. In addition, three preparation methods were introduced: simple polymerization, mixing and reaction processing. The effect of the rare earth/polymer composites pre-sturcture and the coordinate number of rare earth ions on the light property was analyzed. Rare earth/polymer composite may have the structure and property simlar to those of the ionomer. The feasibility of the in-situ preparation of the rare earth/polymer nano structure is indicated. Besides, the relationship between structure and properties of the rare earth/polymer composite was discussed. The problems associated with such composite materials were also presented.

Synthesis, Characterization of A Novel Polymeric Reaction Monomer for Preparing Highly Fluorescent Rare Earth Polymer Materials

A novel polymeric reaction monomer (NPRM) for preparing highly fluorescent rare earth polymer materials was synthesized via interface and coordinating reaction. The composition and structure of the NPRM and intermediate product (ligand) were characterized through the Fourier transform infrared spectroscopy (FT-IR), carbon-nuclear magnetic resonance spectrum (13CNMR), Mass spectra (MS), and element analysis data. The results showed that the composition and structure of NPRM agreed with that of anticipated product. The NPRM was composed of two important sections. Section 1 was able to provide excellent fluorescent properties for final rare earth polymer material through the effect energy transfer between ligand and rare earth ion; Section 2 would endow with the NPRM excellent polymeric active and form highly fluorescent rare earth polymer material. Fluorescent properties of the NPRM were also researched via a CARY ECLIPSE fluorescent spectrometer. The results showed that the NPRM possessed excellent luminescent properties. The corresponding emission peaks based on the 5D0→7F1(601.6 nm), 5D0→7F2(625.0 nm), 5D0→7F3(660.5 nm) and 5D0→7F4(706.3 nm) transitions for Eu3+ were observed. The strongest emission peak was at 625 nm, which belonged to 5D0→7F2 transition.

Synthesis, Characterization and Fluorescence of Rare earth Nitrate Complexes with Triaza-crown Ether Derivative

Four new complexes of rare earths with a triaza crown ether (L) derived from N 3O 2 macro cycle 1,12,15 triaza 3, 4: 9,10 dibenzo 5, 8 dioxacycloheptadecane were synthesized and characterized by elemental analysis, IR, molar conductance, TG DTA analysis and fluorescence spectra. The composition of the complexes determined as [RE(NO 3) 3L·3H 2O]·H 2O (RE=Sm, Eu, Tb and Dy). It is found that Sm 3+ , Eu 3+ , Tb 3+ and Dy 3+ complexes all show strong fluorescence emission in the solid state. Among these complexes, Tb 3+ complex has the strongest luminescence intensity. It shows that the ligand L triplet state energy matches 5D 4 energy level of Tb 3+ . In the Eu 3+ complex, η ( 5D 0→ 7F 2/ 5D 0→ 7F 1) is 2.6, which indicates that Eu 3+ locates at the asymmetric coordination field.

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.

Survival of Pseudomonas fluorescence X16(luxAB)Strain in Soils Accumulated with Mixed Rare Earth Elements

Rare earth elements(REE)are applied as micro-fertilizer in large scale in China and there is growing concern about the environmental effects of REE accumulation in soils. Accumulation of REE was simulated in lab by adding REE to three soils and the survival of Pseudomonas fluorescence X16 strain marked with luxAB gene in soils was detected. Curvilinear regression method was applied to analyze the survival pattern. The stimulation values, EC_(50) and NOEC values for X16 strain were calculated to compare the toxic intensity of REE in different soils. The stimulation(peak)values in red soil, yellow fluovo-aquic soil and yellow cinnamon soil, are 11.55～18.08,(0～2.13), 2.37～4.62 mg·kg^(-1) , respectively. EC_(50) values are 13.47～39.12, 6.59～56.18, 372～1034 (mg·kg^(-1)), respectively.NOEC values are 5.62 ～21.41, 0.00～4.53, 133.3～327.1 mg·kg^(-1), respectively. Tangents values of regression equation of the survival of X16 strain in red soil are the maximum ones indicating that REE accumulation in red soil has stronger inhibitory effects than in other two soils. The soil order, reflecting toxic intensity of REE is as follows: red soil>yellow fluovic-aquic soil>yellow cinnamon soil.

A series of rare earth coordination polymer constructed from paddle-wheel building blocks

Three coordination polymers, Ln2（bpdc）3（phen）2（H2O）2 （Ln=Nd（1）, Eu（2）, and Tb （3）; bpdc=2,2＇-bipyridine-3,3＇-dicarboxylate; phen=1,10-phenanthroline）, were obtained by hydrothermal reaction of Ln2O3 with 2,2＇-bipyridine-3,3＇-dicarboxylate acid, and 1,10-phe- nanthroline. They were characterized by single-crystal X-ray diffraction, IR spectra, and photoluminescent spectra. The crystallographic data of 1-3 indicated that they were isostructural. Both complexes contained paddle-wheel building blocks, formed by bpdc and phen ligands. These paddle-wheel secondary building units （SBUs） were further connected to form two-dimensional （2-D） metal organic framework （MOF） networks by 2,2＇-bipyridine-3, and 3＇-dicarboxylate tinkers. A three-dimensional （3-D） supramolecular structure was formed by π-π aromatic interactions between adjacent 2-D infinite networks. Photoluminescent measurements indicated that europium compound 2 and terbium compound 3 were strong, red and green emitters, respectively.

Preparation and properties of polymeric colloidal crystals containing rare earth complexes

Rare earth organic complexes were introduced into the polymerization system, and the polymeric colloidal nanospheres containing rare earth complexes were prepared by emulsion copolymerization. The characterization results indicated that the polymeric spheres were small at nanometer size and the diameter was monodisperse, particularly the nanospheres possessed good fluorescent properties. Moreover, the polymeric nanospheres were self-assembled to fabricate the colloidal crystals, which were three-dimensional regular multilayer films. The polymeric colloidal crystal films exhibited excellent luminescent and novel optical properties.

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.

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.

A REVIEW ON THE ENHANCED PERFORMANCE OF POLYMER MATERIALS BY INTEGRATING RARE EARTH

Due to excellent, unique and safe properties of rare earth, it is a common method to integrate rare earth with polymer matrices so as to confer their fascinating and complementary properties to the polymer materials, in order to create new composite materials with special properties such as mechanical, thermal, antioxidative, flame retardant, antibacterial properties, etc. Generally speaking, rare earth just plays a synergistic effect on metal oxide and organic ligands. The rare earth addition usually does not exceed 10%.This article is to provide a comprehensive and up-to-date overview for rare earth synergistic effect on the properties of polymers, and present the application of rare earth in improving the properties of polymers.

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.

Preparation and Properties of Rare Earth Modified Carbon Black/Natural Rubber Composites

The oxides Eu, Ho, Er and Dy were used to prepare the hydroxides of rare earth modified carbon black. Then natural rubber latex （NRL） was added into the reactor. The system reacted at 85 ℃ with stirring for 1 h to prepare powdered HAF-Ln（OH）3/NR composites. The effects of the kind and content of Ln on the particle size distribution of P [ NR/HAF-Ln （OH）3 ] and mechanical properties of its vulcanizate were studied respectively. It is found that rare earth can help to get the powder of the composite, the product particle with a diameter less than 0.9mm will be get when the composites containing the compound of Ho, Er and Dy with dosage of 1.0, 1.0, O. 5 percent, respectively. The adding of Ln can improve the tensile strength and tear strength of the vulcanizate effectively, what＇s more, Er and Dy can decrease the permanent set of vulcanizate significantly. The SEM studies shows that P[ NR/HAF-Dy （OH）3 ] vulcanizate shows superior mechanical properties that depend primarily on the absence of free carbon black, the fine dispersion of carbon black in the rubber matrix and better polymer-filler interaction.

Synthesis and characterization of hydrogel bonded with rare earth

Chitosan-poly（acryfic acid） hydrogel bonded with Eu^3＋ was prepared by radical solution polymerization. Biodegradable chitosan, N,N＇-methylen-diacrylamide, and potassium persulphate were used as the basic material, cross-linking agent, and initiator, respectively. The structure and thermal property of hydrogel were characterized by infrared spectrometry, X-ray diffraction, scanning electron microscopy, and differential scanning calorimetry. The swollen property and fluorescent performance were also characterized. The results showed that the rare earth presented unique distribution in the hydrogel due to the formation of chemical bonds after polymerization. The glass transition temperature of the hydrogel decreased remarkably, which might broaden the range of its elastic application considerably. Moreover, the characteristic fluorescent emission of Eu^3＋ was observed in the hydrogel, which was indicative of the excellent luminescent performance.

Synthesis and Characterization of Rare Earth Tesnary Complexes with Cinnamic Acid and O-Phenanthroline

Thirteen solid rare earth tesnary complexes with cinnamic acid C 6H 5CH=CHCOOH, HL and o phenanthroline (phen), RE(phen)L 3 were synthesized. Their IR absorption spectra, molar conductance, TG DTA, X ray power diffraction analysis and fluorescence spectra were studied. The results show that all coordination compounds are oxidized and decomposed around 400 ℃ to 540 ℃. They are all crystalline material. The fluorescence spectra indicate that the fluorescence emission intensity of Eu(phen)L 3 is the highest among them.

Synthesis and Characterization of Rare Earth Complexes of Ferrocenylcarbonylhydrazine

Rare earth complexes of ferrocenylcarbonylhydrazine Ln(FH) x (ClO 4) 3· n H 2O (where Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, x =3; Ln = Er, Tm, Yb, Lu, x =4; n =2～6, FH=ferrocenylcarbonylhydrazin) were synthesized and characterized by elemental analyses, MS, IR and 1H NMR spectra. The ligand FH is bidentate, coordinating through the carbonyl oxygen and the amino nitrogen atom. The redox properties of the ligand and its complexes were investigated using cyclic voltammetric method. The solid state fluorescence spectra of Sm, Tb and Dy complexes were also studied.

SYNTHESIS AND IDENTIFICATION OF CONDUCTING POLYANILINE DOPED WITH RARE EARTH CHLORIDE

Polyaniline doped with rare earth chloride was synthesized in organic solvent and identified by elemental analysis and infrared spectroscopy. The experimental results show that there exists both doping and complexation at the same time in the resulting product. When pH4. Moreover, polyaniline doped with rare earth chloride exhibits better thermal stability than that doped with hydrochloric acid.

Study on Anticoagulation Factor I from Agkistrodon Acutus Venom by Rare Earth Ion Probes

It was observed that rare earth ions (Nd 3+, Sm 3+, Eu 3+, Gd 3+, Tb 3+) have significant quenching effects on the fluorescence of anticoagulation factor I (ACF I). The results of the fluorescence titration of ACF I with rare earth ions demonstrate that ACF I has two RE 3+-binding sites, and the rare earth ions and Ca 2+ bind to ACF I competitively in the two similar sites. The association constants K 1 and K 2 of ACF I with each rare earth ions (Nd 3+, Sm 3+, Eu 3+, Gd 3+, Tb 3+) are close to each other, which indicates the structural similarity of the two binding sites in ACF I. Although the ionic radii of Nd 3+, Sm 3+, Eu 3+, Gd 3+ and Tb 3+ are different, both their K 1 and K 2 are similar, respectively. This reveals the conformational flexibility of the two binding sites in ACF I, which offers a possibility for Ca 2+ to take play in the inducing conformational changes of ACF I and the promoting the binding of ACF I with activated coagulation factor X.

Sensitized Luminescence of Rare Earths

The enhancement effect on the fluorescence intensities of an Eu3+ (or/and Sm3+ )-thenoyltrifluoroacetone (TTA )-dibenzo-18-crown-6 (18-C-6 ) system and Eu 3+ (or /and Sm3+ ) -benzoyltrifluoroacetone (BTA )-cetyltrimethylammonium bromide (CTMAB) system by dysprosium has been studied. In the presence of enhancing ions, the fluorescence intensities of the above systems were enhanced by a factor of about 40-150, respectively. The above systems were used for the determination of europlum or/and samarium in rare earths oxides and gave satisfactory results.

Synthesis,characterization and fluorescence properties of a novel rare earth complex for anti-counterfeiting material

A novel ligand with two ester groups,two benzene rings and two carbox yl groups was synthesized. The composition and structure of the ligand were char acterized by the Fourier transform infrared spectroscopy(FT-IR) ,nuclear magnet ic resonance spectrum(NMR) and UV spectrometer. The rare-earth complex with the ligand and 1,10-phenanthroline(phen) was synthesized and structurally charact erized by FT-IR,TG and fluorescent spectrometer. The results showed that the no vel multicarboxyl ligand could efficiently transfer the energy to Eu3+ ions in t he complex and sensitize the luminescence of the rare earth ions,and the comple x could emit strong fluorescence of the rare earth ions.