Synthesis and Characterization of Rare Earth Complexes with Phthalanilic Acids and Amino Acids

The complexes with the general formula REP3A· H2O [P = 2- (COO ) C6H4CONHC6H4X, X=2-CI, 4-Br; A=Gly, Ala, Leu; RE=Pr3+, Nd3+] were synthesized and characlerized by elemental analysis, IR and reflectance electronic spectra and TG methods. The results show that rare earth ion in each complex is coordinated by three oxygen atoms. One is from the amido and the other two from the hydroxyl in the carboxylate and the amino acid respectively, and each complex contains one coordinate water molecule. Condon parameters Fk, Lande parameters(4f), Nephelanxetic ratio(β), percentage convalency parameter(δ) and bonding parameter(b ) of the chelates were calculated from the reflectance electronic spectra, indicating certain covalent character in the metalligand bond. The apparent decompose activation energies were evaluated and the decompose mechanism were discussed.

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.

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 and Characterization of Lanthanum Complexes with Amino Acid Schiff Base

Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, H-1 NMR, thermogravimetric and differential thermal analysis.

Synthesis, Structure and Luminescent Properties of Three 1D Chain Rare Earth Complexes

Three 1 D chain coordination polymers [Ln(pydc)2(H2 O)2]n·n Him(Ln = Dy(1), Gd(2), Sm(3), H2 pydc = pyridine-2,5-dicarboxylic acid, Im = imidazole), were solvothermally synthesized by the reaction of pyridine-2,5-dicarboxylic acid(H2 pydc), Ln(Ⅲ) salts and imidazole. They have been characterized by X-ray single-crystal diffraction, IR spectra, TGA analysis and elemental analysis. Structural analyses revealed that complexes 1~3 have similar 1 D chain structures and belong to P1 space group. It is noteworthy that complexes 1~3 exhibited excellent thermal stability and no weightlessness below 117 ℃. Meanwhile, 1 and 3 show characteristic fluorescence of corresponding lanthanide metal ions in solid state at room temperature.

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.

Synthesis and Characterization of Rare Earth Solid Complexes with Sodium 5-Aminosalicylate

Ten new rare earth solid complexes were synthesized by the reaction of sodium 5-aminosalicyliate with rare earth chloride. The structure character, physical and chemical properties of these complexes were studied by IR, UV, ()~1H NMR spectra, TG-DTA, fluorescence, elemental analyses, molar conductance and magnetic susceptibility. The ten rare earth complexes exist in dimeric form probably and the coordination number is seven. The antibacterial activity of the ligand and six complexes was also tested against Staphylococcus aureus, Escherichia coli and Bacillus subtilis, and the effect of Yb complex at 20 mg·ml^(-1) against Staphylococcus aureus is most significant.

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.

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.

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, Characterization and Luminescent Properties of Complexes of Rare Earth Nitrates with 2,2′:4′,4″:2″,2- Quaterpyridine

The rare earth nitrate complexes with 2,2′:4′,4″:2″,2 quaterpyridine (L) were prepared in ethylacetate. These new complexes with the general formula [RE(NO 3) 3L]·H 2O (RE = La, Pr, Eu, Tb, Er, Y) were characterized by elemental analysis, IR spectra, thermal analysis and molar conductance measurements. The luminescence properties of these complexes were also studied.

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(V)-SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 2,2'-DINITRO-4,5,4',5'-BIS-(15-CROWN-5)-DIBENZO DISULFIDE

Three new solid complexes of macrocyclic polyether ligand 2, 2'-dinitro-4, 5, 4', 5'bis-(15- crown-5)-dihenzo disulfide(L) with trivalent rare earth nitrates having composition of RE(NO_3)_3·L ·6H_2O(RE=Ce, Pr, Nd) have been synthesized in acetonitrile. All the isolated complexes have been characterized by elementary analysis, IR and UV spectra, differential thermal and thermogravimetric analysis, X-ray powder diffraction analysis, molar conductance and measurements of solubility in some general solvents.

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(Ⅳ)SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 4'-BROMO-5'-NITROBENZO-15-CROWN-5

Six new solid complexes of macrocyclic polyether ligand 4′-bromo-5′-nitrobenzo-15-crown-5(L)with Uivalent rare earth nitrates having composition of RE(NO_3)_3·L·mCH_3CN·nH_2O(RE=L_a--Nd,m=n=0, RE=Sm,Bu,m=0.1,n=1,4)have been synthesized in acetonitrile or acetone.All the isolated complexes have been char- acterized by elementary analysis,IR and UV spectra,differential thermal and thermogravimetric analysis,X-ray powder diffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows that coordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.

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 SYNTHESIS,CHARACTERIZATION AND STRUCTURE OF A NEW RARE EARTH COORDINATION COMPOUND WITH BENZOIC ACID

In this paper,a new rare earth benzoate coordination compound,[TbL_3(HL)(H_2O)]_2 (HL=C_7H_6O_2=benzoic acid) is synthesized and characterized by elemental analysis DTA,TG,DTC,and IR spectra.The title compound crystallizes in triclinic,space.group P with a=9.148(1),b=11.460(2), c=13.506(2);α=112.76(1),β=91.83(1),γ=91.99(1)°;Z=1;V=1303.3.The final R factor is 0.0235.The rare earth ion is nine-coordinated to form a distorted monocapped square antiprism.

In-Situ Synthesis of Terbium Complex with Salicylic Acid in Silica Matrix by a Two-Step Sol-Gel Process

A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic acid have also been discussed with respect to that of the geldoped with terbium and that of pure terbium complex with salicylic acid.

Synthesis of a Polyaminopolycarboxylic Acid and Fluorescence of Tb^(3+) Complexes in Aqueous Solution

A new polyaminopolycarboxylic acid, diethylenetriamine N′,N bi( p acetoamino salicylic acid) N′,N″,N triacetic acid(DTPA·2pAS), has been synthesized DTPA·2pAs can sensitize the luminescence of Tb 3+ and Dy 3+ in aqueous solution Fluorescent titration at pH 7 0 indicated a 1∶1 composition of Tb 3+ to DTPA·2pAS for the complexes The complexes exhibit intensely sensitized fluorescence in a range of pH 5 0～12 0 The fluorescence intensity of the complexes increased as the concentration was raised from 1×10 -7 to 1×10 -4 mol/L, and then decreased at 1×10 -3 mol/L due to concentration quenching A replacement of EDTA with DTPA·2pAs in Tb 3+ EDTA complex solution led to increasement in Tb 3+ sensitized luminescence intensity, suggesting formation of Tb 3+ DTPA·2pAS complexes and higher stability of these complexes than those of Tb 3+ EDTA, which has been confirmed by determination of stability constants with pH potentiometric titration The results show that DTPA·2pAS may be applied to fluorescent immunoassay as a “fluorescence enhancement solution”

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,characterization and fluorescence of N,N'-BIS (6-metyl-2-pyridinecarboxylamide-N-oxide)-1,2-ethane and corresponding rare earth (Ⅲ) complexes

A new ligand, N,N-BIS (6-metyl-2-pyridinecarboxylamide-N-oxide)-1,2-ethane (L) and six lanthanide(Ⅲ) complexes (RE=La, Sm, Eu, Tb, Gd, Yb) were synthesized and characterized in detail. The results indicated that the composition of the binary complexes was determined as [REL(H2O)(NO3)2]NO3·nH2O (n=0-2), and the Eu3+ complex had bright red fluorescence in solid state. Three complexes of Eu3+, Tb3+, and Gd3+ with 6-methylpicolinic acid N-oxide (L’) were also synthesized. The relative intensity of sensitized luminescence for Eu3+ increased in the following order: L>L’. The phosphorescence spectra of the Gd3+ complexes at 77 K were measured. The energies of excited triplet state for the ligands were 20704 cm-1 (L) and 20408 cm-1 (L’). The facts that the ligands sensitized Eu3+ strongly and the order of the emission intensity for Eu3+ complexes were explained by ΔE(T-5D). This meant that the triplet energy level of the ligand was the main factor to influence RE3+ luminescence.