Synthesis,Characterization and Antibacterial Properties of Rare Earth (Ce^(3+) ,Pr^(3+) ,Nd^(3+) ,Sm^(3+) ,Er^(3+) ) Complexes with L-Aspartic Acid and o-Phenanthroline

Five novel ternary complexes of rare earth ions with L-Aspartic acid (Asp) and o-phenanthroline (Phen) were synthesized in ethanol aqueous solution. Their compositions were characterized by elemental analysis, molar conductance, FT-IR, Raman, UV-VIS and TG-DTA. The compositions of the complexes were confirmed to be: RE( Asp)3PhenCl3·3H2O (RE: Ce3+ , Pr3+ , Nd3+ , Sm3+ , Er3+ ). The antibacterial activity test shows that all these complexes exhibit excellent antibacterial ability against Escherichia coli, Staphylococcus aureus and Candida albicans. The antimicrobial spectrum of the complexes are broad.

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.

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.

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.

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.

Syntheses, Characterization and Antitumour Activities of Rare Earth Metal Complexes with 2-(((4,6-dimethyl)-2-Pyrimidinyl)thio)-Acetic Acid

Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and ^1H- NMR. The results reveal that carboxyl group of the hgand coordinates with rare earth ions in bidentate mode after deprotonated. The water molecules exist as crystal water in the complexes. The anti-tumour activities of HL and some complexes were tested by both the MTT and SRB methods. The results show that the suppression ratios of some complexes against the tested tumour cells （HL-60 human leukemia cell lines, BGC-823 human gastric carcinoma cell lines, hela human cervix adenocarcinoma cell lines and Bel-7402 human hepatic carcinoma cell lines） are superior to HL.

pH-Potentiometric Study on Rare Earths and Calcium Binary and Ternary Complexes with DL-Malic Acid and L-Hydroxyproline

The stability constants of ML binary system and MLL′(M=La^3+～Yb^3+, Y^3+ and Ca^2+; L=DLmalic aicd, L′=Lhydroxyproline) ternary system were determined by pHpotentiometric method under the simulating physiological condition(37 ℃, I=015 mol/L NaCl). The complex species MpLqL′rHs(abbr as pqrs) in the sytems were ascertained by program COMPLEX. The results show that there are three species(1101, 1100 and 1200) in ML binary system and one species(1010) in ML′ binary system. In addition to the above four species, a new species, 1112 was found in the MLL′-ternary system, which is the only species of mixed ligands. Rare earth ions form more stable complexes than calcium ion does and the stability differences between their complexes in the ternary system are less than that in the binary system. The distributions of all the species in LaLL′-ternary system vs pH are discussed.

Syntheses aod Crystal Structures of Rare Earth Complexes with Adamantanecarboxylic Acid, [LnL_3(HL)(H_2O)]_2·2EtOH·2H_2O (Ln=Nd (1), La (2))

The title complexes （LnL3 （HL） （H2O） ]2· 2EtOH·2H2O （Ln= Nd （1）, La （2）, HL=adamantanecarboxylic acid） were prepared and determined by single-crystal X-ray diffraction. Both complexes crystallize in triclinic system with space group P 1^-, cell parameters are： complex （1） a = 1.0556（2） nm, b =1.4913（3） nm, c = 1.4920（3） nm, a = 106.26 （3）°, β=93.51（3）°, γ=97.23（3）°, V=2.2253 （5） nm^3, Dcal=1.409 g · cm^-3, Z = I , F （ 000 ） = 990, μ（Mo Kα） = 1. 225 mm^-1, M, = 1884.50; complex （2） a = 1.0453（2） nm, b = 1.4971（3）nm, c = 1.5052（3） nm, α = 106.07（3）°, β =93.58 （3）°, γ=97.56（3）°, V=2.2391（5）nm^3, Dcal= 1.397 g·cm^-3, Z = 1, F（000） =984, μ（Mo Kα） = 1.015 mm^-1, Mr= 1877.88. The final R and wR are 0. 0396 and 0. 1062 for 8589 （1 ≥ 2σ （I）） observed reflections for complex （1）, 0.0505 and 0. 1344 for 8417 （ 1 ≥ 2σ （1） ） observed reflections for complex （2）, respectively. The crystals are consisted of a binuelear molecule. The coordination geometry of the Ln（ Ⅲ ） ion can be described as trieapped trigonal prism.

Synthesis and Complexing Properties of Three Aminopolyphosphonic Acids with Rare Earth Ions

Three white crystalline aminopolyphosphonic acids, DTHMP, TTHMP and TPHMP were synthesized by a modified Mannich reaction under gentle conditions. The products were isolated and purified with a SP-Sephadex C-25 column. The acid-base and complexing properties of three aminopolyphosphonic acids with rare earth ions were investigated by means of potentiometric titration in aqueous medium at (25 +/- 0.1) degrees C and ionic strength I = 0.1 mol/L KNO3. The successive protonation constants of ligands and the formation constants of complexes with rare earth elements were obtained. The results show a double-double effect for lgK(MHiL) against atomic number of lanthanide. The properties are advantageous for the separation of the rare earth elements.

THE CRYSTAL STRUCTURE OF RARE EARTH COMPLEX WITH AMINO ACIDS Ⅱ The Crystal Structure of Gtutamate Comptex of Erbium Perchtorate

The crystat structure of {[Er;（L—Glu）;（H;O）;]（ClO;）;·3H;O);has been studied by X-ray diffraction. The crystal is monoctinic with space group P2;and cell parameters a=19.987（3） , b=16.505（3） , c=11.040（2） , β=104.69（1）;, V=3538（1） , Z=2, Dc=2.29 g. cm;, μ=53.2 cm;, F（000）=2384. The asymmetric unit contains two complex motecules and four centre ions. Each erbium （Ⅲ） is coordinated by five oxygen donors from four different glutamates and four oxygen donors from the aqua ligand to form a nine coordination potyhedron. The mean distances of Er—0 （carboxylate） and Er—Ow are 2.439 and 2.41 respectivety. The finat R and Rw are 0.043 and 0. 058, respectivety.

Synthesis,Characterization and Fluorescence Properties of Europium,Terbium Complexes with Biphenyl-4-Carboxylic Acid and o-Phenanthroline

Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen) L3·1/2H2O; Tb (phen) L3·H2O and Tb0.5 RE0.5(Phen)L3·1/2H2O. (RE = Y3+, La3+ and Gd3+; L = biphenyl 4-carboxylic acid; phen = o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE (III ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 + is raised by inert fluorescent rare earth ions (Y3+ , Gd3+ and La3+ ), but in Tb3+ hetero-nuclear rare earth complexes the intensity of Tb3+ ions are quenched by the inert fluorescent rare earth ions.

Preparation of Ternary Lanthanide Complexes with Unsaturated Acid and 1,10-Phenanthroline, and Their Anti-Inflammatory Action

Four ternary lanthanide complexes with unsaturated acid and 1,10-phenanthroline are prepared in methanol and characterized by elemental analysis, molar conductance, UV, IR, (()~1H) NMR and XPS. The results from this paper show that the complexes Ln(phen)(SA)_3·2H_2O or Ln(phen)(CA)_3·H_2O (Ln=Ce(Ⅲ), Sm(Ⅲ) and Eu(Ⅲ), (phen=1,10-)phenanthroline, SA=Sorbate and CA=Cinnamate) has better anti-inflammatory effect than cerium nitrate and their gremores are steadier than cerium nitrate gremor. And there is a kind of medicament which can replace the cerium nitrate gremor completely in treating burn.

Crystal Structure and Luminescence Property of Lanthanide Complexes with 2-Fluorobenzoic Acid and 2,2′-Bipyridine

The two compounds of [Ln（2-FBA）3·2,2＇-bpy ]2（2-FBA = 2-fluorobenzoato, 2,2＇-bpy = 2,2＇-bipyridine, Ln = Eu（1 ）, Dy（2）） were synthesized and their structures were determined by X-ray diffraction method. Crystallized complexes 1 and 2 are isomorphous, monoelinie system with P21/n space group. The two complexes are binuclear molecule with an inversion center. The two lanthanide ions are linked by four bridged 2-FBA ligands and each lanthanide ion is further bonded to one chelated bidentate 2-FBA ligand and one 2,2＇-bipyridine molecule. The coordination number of metal ion is eight. The europium complex exhibits strong red fluorescence. ^5D0→^7Fj（j = 1 - 4） transition emission of Eu^3＋ ion was observed.

Synthesis, Characterization and Fluorescence of Terbium(Ⅲ) Complexes with Phenylglyoxylic Acid and 2,2-Dipyridine, 1,10-Phenanthroline, Triphenyl Phosphine Oxide

Three new complexes TbL3dipy （H2O）2, TbL3phen （H2O） 2 and TbL2 （TPPO） 2NO3 were synthesized （L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1,10-phenanthmline, TPPO = Triphenyl phosphine oxide）. Elemental analysis, conductivity, IR spectra, and ^1HNMR spectra studies were performed. IR spectra indicate that the carboxylate ion of phenylglyoxylate is coordinated to the Tb（Ⅲ） ion as an unidentate ligand. In ^1HNMR, the signals of different hydrogens in phenylglyoxylate ion shift upfield. The excitation and emission spectra of the three solid complexes were recorded at morn temperature, in which the optimum excitation wavelengths are, 361.0, 359.0 and 367.0 nm for these three complexes, respectively. Four emission bands due to the ^5D4-^7Fj（j = 6, 5, 4, 3） transitions were observed for TbL3dipy（H2O）2（489.0, 545.0, 584.0, 620.0 nm） and TbL3phen（H2O）2（490.0, 544.0, 583.0, 620.0 nm）. Under the same conditions, only one emission band due to the ^5D4-^7F5 transition was observed for the complex TbL2（TPPO）2NO3. The emission intensity of TbL3dipy（H2O）2 is the strongest among the three complexes.

Study of Complexes of Lanthanum with Amino Acids by Titration Calorimeter

The stability constants and thermodynamic functions for complexes of lanthanum with eight kind of amino acids according to 1∶1 and 1∶2 in proportion have been determined by titration calorimeter at 298.15 K. The enthalpy change makes a predominant contribution to the stability of these complexes. The ring in amino acid associated with lanthanum ion helps to enhance the stability of complexes. Steric effects between rings in complexes leads to that the equilibrium constants of reaction of the complexes (1∶2) is much less than that of the complexes (1∶1).

Synthesis and Crystul Structure of Lutetium Complex with Triethylenetetraaminehexaacetic Acid (H_6ttha):{[Lu_2 (ttha) (H_2O)_6Lu_2 (ttha) (H_2O)_4]·21H_2O}_n

The title complex was synthesized in an aqueous solution and its crystal structure was determined by X-raydiffraction method. It crystalizes in triclinic crystal system, space group P1, formula C36H110N8O55Lu4, Mr=2235.2,a=1.09787(7) nm, b=1.27603(10) nm, c=1.45903(10) nm; α=75.769(6)°, β=85.288(5)°, γ=71.577(6)°, V=1.8797(2) nm3,Z=1, Dc= 1.975 g·cm-3, F(000)=1106, μ=5.312 mm-1; R1=0.0239, wR2=0.0527 for 7156 reflections with I>2σ (I). In the complex, the lutetium ion is coordinated by two nitrogen atoms andsix oxygen atoms and the coordination number is 8. Its coordination polyhedron can be described as a distorted squareantiprism. The complex is of an infinite chain structure. The complex was characterized by elemental analysis, IR spectra and thermal analysis.

Thermochemical Study on Coordination Complex of Samarium with Salicylic Acid and 8-Hydroxyquinoline

The coordination complex Sm（C7H5O2）2·（C9H6NO）, synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline, was characterized with IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [ SmCl3·6H2O （s） ], [ 2C7H6O3 （s） ], [ C9H7NO （ s ） ] and [ Sm （C7H5O3） 2·（ C9H6NO ） （ s ） ] in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be △sHm^- [ SmCl3·6H2O （s）, 298.15 K ] = - 103.98 ± 0.04 kJ·mol^-1, △sHm^- [2 C7H6O3 （s）, 298.15 K] = 16.35±0.14 kJ·mol^-1,△sHm^-[C9H7NO （s）, 298.15 K] = -6.11±0.08 kJ·mol^-1 and △sHm^-[Sm（C7H5O3）2·（C9H6NO） （s）, 298.15 K] = - 130.08 ± 0.04 kJ·mol^-1, respectively. The enthalpy was determined to be △rHm^- = 89.59 ±0.18 kJ·mol^-1 for the reaction SmCl3·6H2O（s） ＋ 2C7H6O3（s） ＋ C9H7NO（s） = Sm （C7H5O3） 2·（C9H6NO） （ s ） ＋ 3HCl （g） ＋ 6H2O （ l ）. According to the above results and the data given in literature and through Hess＇ law, the standard molar enthalpy of formation of Sin（ C7H5O3 ）2·（C9H7NO）（s） was estimated to be △rHm^- [ Sm （C7H5O3）2·（C9H6NO） （s）, 298.15 K] = - 2055.9 ± 3.03 kJ·mol^-1.

Fluorescence Properties of Eu^(3+)/Gd^(3+)/Citric Acid Mixed Complexes Doping in Silicon Rubber Matrix

Series of doped rare earth compiexes-EuxGd(1-x) (CA)3·nH2O (CA = citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth complexes have the best fluorescence property when the ratio of Eu and Gd is from 0.7 to 0.3. Silicon rubber-based composites were prepared by mechanical blending the EuxGd(1-x) (CA)3·nH2O and silicon rubber. Then, the fluorescent property of the composites was studied. It is found that the fluorescence intensity of the composites increase linearly with the contents of the rare earth complexes increasing.

Synthesis and Characterization of Terbium-Trimesic Acid Luminescent Complex in Polyvinylpyrrolidone Matrix

Tb（Ⅲ ）-trimesic acid （TMA） luminescent complexes were synthesized in the polyvinylpyrrolidone （PVP） matrix. The elemental analysis, inductively coupled plasma-atomic emission spectroscopy （ICP-AES） and fourier-transform infrared spectroscopy （FT-IR） indicated that its chemical constitution is PVP/Tb（MTA）· 4H2O. The XRD patterns showed that the complex is a new kind of crystal. The TEM image indicates that the complex is rod shaped. The rod diameter is about 200 nm, and the length ranges from hundred of nanometer to a few micrometers. In addition, the dispersity is better. TG-DTA curves indicate that the complex is thermally stable before 463℃. Photoluminescence analysis indicates that the complex emits Tb^3＋ characteristic luminescence under ultraviolet excitation.

Synthesis, Structure and Fluorescence Properties of Tb(Ⅲ) Complex with Isonicotinic Acid and Biphenyl-2,2′-Dicarboxylic Acid

Terbium perchlorate reacted with isonicotinic acid （Hpya） and biphenyl-2,2＇-dicarboxylic acid （H2dpa） under hydrothermal condition, a new ternary terbium complex [ Tb （pya） （dpa） （H2O） n （ 1 ） was synthesized. The structure of the ternary complex was determined by X-ray single crystal diffraction and characterized by elemental analysis, fluorescence measurement. The fluorescence spectrum shows the title complex emits strong green light. The crystal data for the com- plex： monoclinic, P21/n space group, a =0.8908（5）nm, b = 1.0569（6）nm, c =2.0969（11）nm, β = 98.446（8）°, V = 1.9528（18） nm^3, Z = 4, R = 0.0241, wR2 = 0.0534. The center Tb3＋ ion is eight coordinated. The coordination polyhedron around Tb3 ＋ ion can be described as a distorted square antiprism. The complex forms an infinite one-dimenand sional alternating chain polymer by bridging carboxyl groups of pyadpa.