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.

Synthesis, Characterization and Vulcanizing Properties of Rare Earth Complexes with 2-Mercaptobenthiazole

Eight complexes of rare earth with 2 mercaptobenthiazole, RELCl 2·RE(OH) 3· x H 2O (L=2 mercaptobenthiazole, RE= La～Gd, Y, except for Pm, x =0, 2～4), were synthesized in unhydrous ethanol and characterized by elemental analyses, IR spectra and thermal analyses. The results show that the ligand is coordinated to the RE ion through both the exocyclic sulfur and the thiazole nitrogen. The vulcanizing properties of the La complex as accelerator were studied in the traditional tire rubber, which indicate that the cross linked rubber accelerated by the rare earth complex has good physical and dynamic mechanical properties by comparison.

Synthesis, characterization, and biological properties of nano-rare earth complexes with L-glutamic acid and imidazole

Four nano-rare earth ternary complexes of L-glutamic acid and imidazole RE（Glu）3ImCl3·3H2O （RE=Ce^3＋, Pr^3＋, Sm^3＋, Dy^3＋, Glu= L-glutamic acid, and Im=imidazole） were synthesized. Their composition was characterized with elemental analysis, IR, and molar conductance. The TEM image indicated that the complexes were regular shaped and the length was about 30-60 nm. The antibacterial activity test showed that all these complexes exhibited better antibacterial ability against Escherichia coli, Staphylociccus aureus, and Candida albican （MIC were about 180, 100, and 310 μg/mi, respectively） and could be considered as broad-spectral antimicrobial. Their antitumor activity in vitro against leukemia K562 cells was measured using the MTr method. The results indicate that the four complexes possess strong inhibi- tion effect on leukemia K562 cells. An approximately linear relationship is discovered between the relative inhibition rate and concentration, with the correlation coefficients R〉0.7 and P〈0.05, which is considered statistically significant.

Interaction between Ternary Rare Earth Complexes of Cinnamic Acid and Phenanthroline with DNA by Spectroscopy

The interaction of ternary complexes [RE(phen)(cin)_3(H_2O)](RE= Nd (III),Ce(III),Eu(III))with calf thymus DNA was investigated by electronic absorption spectroscopy, ethidium bromide(EB)-DNA quenching fluorescent spectra and resonance light scattering. All experimental results indicate that the three complexes bind to DNA by the electrostatic mode and the intercalative mode. It is predicted that these complexes show high anticancer activity or other biologic activity.

Luminescent Properties of Bi-Rare Earth Complexes with m-methylbenzoic Acid and 1,10-phenanthroline

The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m MBA=m methylbenzoate and phen=1,10 phenanthroline. The luminescence properties of the title complexes were studied in comparison with the corresponding complexes Eu 2( m MBA) 6(phen) 2·2H 2O and Tb 2( m MBA) 6(phen) 2·2H 2O respectively. The results indicate that the emission intensity from europium ion can be greatly enhanced by the terbium ion, while the emission from terbium ion was strongly quenched by europium ion in EuTb( m MBA) 6(phen) 2·2H 2O; the emission intensity from terbium ion can be greatly enhanced by yttrium ion in TbY( m MBA) 6(phen) 2·2H 2O. The mechanism about the results was discussed.

Study on Luminescence Properties of a Novel Rare Earth Complex Eu(TTA)_2(N-HPA)Phen

A novel rare earth complex Eu（TTA）2（N-HPA）Phen （TTA = thenoyltrifluoroacetone, N-HPA = N-phenylanthranilic acid, and phen = 1,10-phenathroline ）, which contains three different ligands, was synthesized. The Eu complex was blended with poly N-vinylcarbazole （PVK） in different weight ratios and spin coated into films. The luminescence properties of films were investigated and energy transfer between PVK and the complex was discussed. Multilayer structural devices consisting of ITO/PVK： Eu （TTA）2 （N-HPA） phen/BCP/Alq3/Al were fabricated with PVK ： Eu （TTA）2（N-HPA） as light-emitting layer. Increasing the concentration of Eu in the PVK thin film would inhibit the emission of PVK to different degrees. Finally, the pure red luminescence of europium（ Ⅲ ） was observed when the doping weight ratio was approximately 1 ： 5, which indicated an effective energy transfer from PVK to rare earth complex.

RING-OPENING POLYMERIZATION OF TRIMETHYLENE CARBONATE CATALYZED BY NOVEL SINGLE COMPONENT RARE EARTH CALIXARENE COMPLEXES

In this paper,ring-opening polymerization of trimethylene carbonate(TMC)with rare earth(Nd,Y,La)ρ-tert- butylcalix[n]arene(n=4,6,and 8)complexes as catalysts has been studied.Poly(trimethylene carbonate)(PTMC)with M_v of 21,400 was produced by bulk polymerization under the conditions as follows:[TMC]_0/[Nd](molar ratio)=1000,80℃, 8 h.Mechanism study reveals that the polymerization proceeds via a coordination mechanism.

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, Characterization and Luminescent Properties of MCM-41 Type Materials Impregnated with Rare Earth Complex

Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.

Synthesis and luminescence properties of rare earth ternary complexes consisting of Tb(Ⅲ), β-diketones and 1,10-phenanthroline (phen)

In order to study the luminescent properties of ternary rare earth complexes with fl-diketone ligand, three new β-diketone ligands, 1-phenyl-3-（p-phenylethynylphenyl）-1,3-propanedione（HPPP）, 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HTPP） and 1-（2-furyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HFPP）, were synthesized by Sonogashira coupling reaction and Claisen condensation. Three new ternary rare earth complexes, TbL3phen （L = PPP, TPP, or FPP）, were synthesized by the reaction of rare earth chloride TbCl3,1,10-phenanthroline （phen） with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Yb（Ⅲ） complexes only emit the weak fluorescence of the Tb（Ⅲ） ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb^3＋ ion.

Synthesis and Crystal Structure of Rare Earth Complex withCiprofloxacin

The complex of rare earth with ciprofloxacin has been synthesized and characterized by means of x-ray single crystal diffraction. The structure features of the complex are decribed.

Synthesis and Photoluminescence Properties of Rare Earth Complexes with 3-Allyl-2, 4-Pentanedione

In order to combine the merits of rare earth organic complexes with excellent material performances of polymers, a polymerizable chelating agent, 3-allyl-2, 4-pentane dione (APD), was synthesized by phase transfer catalysis and its rare earth complexes were prepared. The compounds were characterized by EA, IR and (()~1H NMR.) Their UV spectra and fluorescence spectra were investigated. The effects of allyl on the luminescence properties of the complexes were studied. The results show that the sensitization of APD is changed by allyl in comparison with that of acetyl acetone (acac), and it becomes an ideal novel ligand of Eu. In addition, intramolecular energy transfer mechanism in the luminescence process in the complexes was also discussed in detail.

Study on Copolymerization of Rare Earth-Carboxylic Acid Complex

Complex of rare earth with carboxylic acid was prepared by precipitation and direct method. It was copolymerized with such monomers as acrylic acid and other ones to synthesize ionomer of rare earth and organic polymer with different rare earth contents. Its glass-transition temperature and heat stability were analyzed by TG and DTA. Infra-red detector was used to show its structure. The effect of rare earth complex prepared by different methods on copolymerization and properties of copolymers was also discussed.

Effects of Rare Earths and Its Complex with Extract from Seaweed (Laminaria japonica) on Growth and Immunization of Penaeid Shrimp (Penaeus vannamei)

The effects of rare earths (RE) and its complex with extract from seaweed (Lamiaria japonica) on the growth and immunization of penaeid shrimp (Penaeus vannamei) were investigated. The results show that the survival rate, body length and weight of the shrimp treated by RE and its complex with extract from seaweed are higher than those of the control, and that the activities of the phenoloxidase (PO), lysozyme (LSZ), superoxide dismutase (SOD), peroxidase (POD), acid phosphatase (ACP) and alkaline phosphatase (ALP) in the shrimp treated by RE and the complex are also much higher than those from the control.

An Encapsulation of the Rare Earth Complex in Modified Mesoporous Molecular Sieve MCM-41

The encapsulation of a rare earth (RE) complex Eu(DBM)(3)phen in modified S1-MCM-41 with 3-aminopropyltriethoxysilane is reported for the first time. The luminescence intensity of the RE complex in the modified Si-MCM-41 is about 9 times as strong as in unmodified Si-MCM-41 and the luminescence of the RE complex in the modified SI-MCM-41 has good color purity.

Syntheses and Infrared Spectra of Rare Earth Complexes with Diethyl Phosphate

The title complexes Ln(DEP),(Ln=La,Sm,Eu,Ho and Yb)were synthesized by reaction of triethyl phosphate with trivalent rare earth chlorides.The mechanism of thermo-decomposition of the complexes has been studied.According to their IR spectra,the residues of the thermo-decomposition of the complexes were identified as Ln(PO_3)_3.Their IR spectra were measured and principal IR bands were assigned.The experimental results of the IR spectra of the complexes show that the title complexes have the same coordination form and mo- lecular configuration as rare earth,e.g.Sm,complex with dimethyl phosphate(Sm(DMP)_3).Each of the rare earth ion links three rare earth ions nearby through double“O-P-O”bridges to form a special network of rings-linking-rings,each of which consists of twenty-four atoms.The Ln-O bond is principally ionic.

The Luminescence Properties and Intramolecular Energy Transfer of Rare Earth Complexes with Aromatic Carboxylic Acids

The triplet state energies of para aminobenzoic acid and nicotinic acid were determined by means of low temperature phosphorescence spectrometry. The energy matches between them and the resonant emitting energy levels of Eu 3+ , Tb 3+ , Sm 3+ , Dy 3+ were studied. The intramolecular energy transfer processes from the two aromatic carboxylic acid ligands to rare earth ions were also discussed on the basis of the measurement results of luminescence intensities, lifetimes and quantum efficiencies.

Preparation and Properties of Rare Earth Complexes with 5-Phenyl Pyrazoline Dithioformate

Nine complexes of rare earths with 5 phenyl pyrazoline dithioformate, Na[RE(S 2CNC 9H 9 N) 4· x H 2O (RE=La～Dy, Y, except for Ce and Pm) were synthesized in dry N 2 atmosphere and characterized by elemental analyses, molar conductance, IR spectra, thermal analyses. The results show that the ligands coordinate to the RE ion through two sulphur atom donors. Thermal analyses indicate that the thermal stability of the complex is not higher than that of sodium 5 phenyl pyrazoline dithioformate. The complexes are easily soluble in acetonitrile and tetrahydrofuran. The molar conductance values of the complexes measured in acetonitrile (1 24～1 32×10 -3 mol·dm -3 ) at 25 ℃ are in the range of 86～104 Ω -1 ·cm 2·mol -1 , indicating that they are 1∶1 electrolytes.

Synthesis and spectroscopic characterization of fluorescent solid rare-earth complexes with hydroxamic acids

The complexes RE_2(DHYA)_3 centre dot nH_2O in the title bar were synthesizedthrough some reactions of trivalent rare-earth ions. In the process of synthesis, dihydroxamicacids were taken as ligands while the alcohol was taken as a solvent. The ligands includedadipylhydroxamic acid (ADHA), p-phthalichydroxamic acid (PPHA), oxalohydroxamic acid (OXHA),butadihydroxamic acid (BDHA), o-phthalichydroxamic acid (OPHA), benzoylhydroxamic acid (BHA), etc.Measured at 25 deg C, the molar conductances in various modes are 13.00-21.05 S centre dot cm^2centre dot mol^(-1), which shows that rare-earth complexes are nonelectrolytes and the hydroxaminogroups of the complexes have taken part in bonding. Infrared spectra, ultraviolet spectra, nuclearmagnetic resonance (~1HNMR) spectra, and fluorescence spectra were used to investigate thecomplexes. Experiments have proved that the complexes of En^(3+)and Tb^(3+) with aromatic hydroxamicacids have good fluorescent characteristics.

Complex behaviour of trivalent rare earth elements by humic acids

The complexation behaviours of trivalent rare earth elements (La, Ce, Ho and Yb) by two types of humic acids were investigated under a specified set of conditions. Humic acids show quite different complexation capacities an conditional formation constants with the REEs. Apparently there are two types of binding sites in the functional groups of humic acid, in which the first binding sites have stronger ability than the second. Cerium shows the largest complexation capacities and highest formation constants among the four REEs with two humic acids, this anomaly may be relative to the distribution pattern of the REEs in seawater. The experimental results were comparable to the values of other metals reported and provided the basic data for environmental geochemistry of rare earth elements.