Synthesis,characterization, biological activities and luminescent properties of lanthanide complexes with [2-thiophenecarboxylic acid, 2-(2-pyridinylmethylene)hydrazide] Schiff bases ligand

A Schiff base L [2-thiophenecarboxylic acid, 2-(2-pyridinylmethylene)hydrazide] with its lanthanide metal complexes was synthesized. These complexes were characterized by elemental analysis, molar conductivity measurements, spectral analysis(NMR, FT-IR, and UV-Vis), luminescence and thermal gravimetric analysis. The Schiff base ligand was a tridentate chelate and coordinates to the central lanthanide ion with 1:2 metal:ligand ratio. The conductivity data showed a 1:1 electrolytic nature with a general formula [LnL_2(NO_3)_2]NO_3. The luminescence emission properties for Sm, Tb, and Eu complexes were observed and showed that the ligand L could absorb and transfer energy to Sm(III), Tb(III) and Eu(III) ions. The complexes possessed a good antibacterial activity against different bacterial strains. In addition, the scavenging activity of the Ln(III) complexes on DPPH was concentration dependant and the complexes were significantly more efficient in quenching DPPH than the free Schiff base ligand.     

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

Sinceaza crownethershowsspecialcoordinationpropertiestotransitionmetalandheavymetalions[1,2 ] ,therearemanyreportsofthecomplexesinhost guestchemistry ,molecularrecognition[3 ,4] andionophoreinmembranetransportation[5] ,butthereislittlereportontheirrareearthscomplexesandthefluorescenceaboutthecomplexes[6] ,andthefluorescenceintensityoftheircomplexesarenotverystrong .Weinsetbenzoylgroupintothemacrocycle ,expectingthatitsrareearthscomplexeshavebetterfluorescenceproperties .Inthispaperthesynthesis…     

Highly luminescent europium and terbium complexes based on succinimide and N-hydroxysuccinimide

The preparation of two highly luminescent europium(III) and terbium(III) complexes with succinimide(SI) and N-hydroxysuccinimide(NHSI) were reported,which were further investigated through elemental chemical analysis,thermal analysis,FT-IR,powder X-ray diffraction,SEM and fluorescence spectroscopy.Data collected through these analysis revealed the formation of the Eu(III) and Tb(III) complexes with the above mentioned ligands at a metal to ligand(M:L) molar ratio of 1:3.Interesting conclusions regarding the efficient sensitization through the coordination site of the lanthanide luminescent centers were retained from the photoluminescent spectra investigation.Strong luminescence emission was observed in case of Eu(III)-SI and Tb(III)-NHSI complexes while the corresponding Eu(III)-NHSI and Tb(III)-SI complexes exhibited no photo luminescent properties.Newly obtained luminescent lanthanide complexes may be of particular interest for various applications in optoelectronics.     

Metal-organic frameworks of lanthanide iminodiacetates and tartrates:Synthesis,structural characterization and luminescence properties——Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

Two series of lanthanide-containing metal-organic frameworks(Ln-MOFs) of the general formula{[Ln(HIDA)_2 H_2 O]ClO_4·H_2 O}_n(Ln = La(1),Nd(2),Eu(3),Gd(4),Tb(5),Eu:Tb(6);H_2 IDA=iminodiacetic acid) and [Ln(TT)(HTT)(H_2 O)_3]_n(Ln=Eu(7),Gd(8),Tb(9),Dy(10),and Eu:Tb(11);H_2 TT=tartaric acid)were synthesized by reacting Ln(ClO_4)_3 with iminodiacetic acid and L-tartaric acid,respectively.All compounds were structurally characterized by single-crystal X-ray diffraction.Elemental analyses are co nsistent with the corre sponding crystallographically generated formulas.Mo reover,the luminescence properties of both the single and mixed-lanthanide complexes were studied.Near infrared,red,and green emissions that are characteristic of Nd(Ⅲ),Eu(Ⅲ),and Tb(Ⅲ) are observed for 2,3/7,and 5/9,respectively.For the two mixed-lanthanide complex systems 6 and 11,depending on the relative amount of Eu(Ⅲ) and Tb(Ⅲ),the color of emission can be fine-tuned.It is found that a small amount of Eu(Ⅲ) is adequate for the observation of the most intense transition of Eu(Ⅲ).This is believed to be a result of energy transfer from Tb(Ⅲ) to Eu(Ⅲ) within the same complex-a conclusion supported by the significantly shortened lifetime of Tb(Ⅲ) and the accompanying enhanced lifetime of Eu(Ⅲ) in the mixedlanthanide complex with respect to the corresponding values for the pure Tb(Ⅲ) and Eu(Ⅲ) complexes with the same ligand.     

Syntheses and Characterization of Binuclear Complexes Tb（1-x）Eux（TTA）3 Phen

Rare earth ternary complexes Tb1-xEux（TTA）3Phen（x=0,0.25,0.5,0.75,1.0）were synthesized and characterized by DTA-TG,XRD and infrared（IR）.The photophysical properties of these complexes were studied in detail using ultraviolet absorption spectra and fluorescent spectra.Ultraviolet absorption showed that the energy absorption of the complexes mostly came from ligands.Infrared spectra of Tb1-xEux（TTA）3Phen complexes were similar to the pure complexes.TG curves proved that the complexes were stable.Tb3＋ emission was almost quenched and the Eu3＋ emission was enhanced by codoping the complexes.The Tb3＋ ion acted as an energy transfer bridge that helped energy transfer from poly（N-vinylcar-bazole（PVK）to Eu3＋.In addition,their PL and EL properties were systematically studied.     

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. Photoluminescent measurement showed that ligand ABMF could efficiently transfer the energy to Sm3+ and Eu3+ ions in the complexes and sensitize the luminescence of the rare earth ions, but could not sensitize Tb3+ and Dy3+ ions. As a result, both Sm3+ and Eu3+ complexes emitted the characteristic fluorescence of Sm3+ and Eu3+ ions due to the f-f transitions. The four copolymers could emit strong fluorescence of the rare earth ions.     

Synthesis and luminescent properties of novel pyrazolone rare earth complexes

A novel pyrazolone pyridine-containing ligand,2,6-bis(1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl)pyridine (H2L) was de-signed and synthesized from pyridine-2,6-dicarboxylic acid (1),and its Eu(III) and Tb(III) complexes were prepared.The ligand and com-plexes were characterized in detail based on FT-IR spectra,1H NMR,elemental analysis and thermal analysis,and the formula of Ln2L3·4H2O (Ln=Eu or Tb) of rare earth complexes was confirmed.The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated,which showed that the Eu(III) and Tb(III) ions could be sensitized efficiently by the ligand (H2L) and emit the photolumi-nescence with high intensity,narrow half-peak width,and monochromic light.The results indicated that the complexes showed potential as excellent luminescent materials.     

Use of sensitized luminescence of lanthanides in analysis of drugs

The sensitization of the Tb(III) and Eu(III) ions luminescence by drugs, the pyrocatechol, naphthyridine and heterocyclic aromatic acid derivatives, were studied. It was shown that a result of intramolecular energy transfer from the ligand molecule to the lanthanide ion increases the luminescence intensity of the latter by 10(8)-10(10) times. The luminescence properties of the complexes in solutions were investigated. The highly sensitive methods for luminescence determination of dopegyt, levodopum, dophaminum, nevigramon, furosemidum and cinchophenum were developed. The detection limits of the drugs are 0.0005, 0.02, 0.5, 0.01, 0.05 and 0.1, respectively.     

Synthesis, characterization, cytotoxicity, DNA cleavage and antimicrobial activity of homodinuclear lanthanide complexes of phenylthioacetic acid

Lanthanide complexes of Eu(III), Gd(III), Nd(III), Sm(III), and Tb(III) with phenylthioacetic acid were synthesized and characterized by elemental analysis, mass, infrared radiation (IR), electronic sp...     

Photophysical properties of a new ternary europium complex with 2-thenoyltrifluoroacetone and 5-nitro-1,10-phenanthroline

A ligand, 5-nitro-1,10-phenanthroline (phenNO2), was synthesized. Its Eu(III) complex with 2-thenoyltrifluoroacetone (HTTA) was prepared and characterized by elemental analysis, IR and 1H NMR spectra. The photophysical properties of the complex were studied in detail by using UV, luminescence spectra, luminescence lifetime and quantum yield. The complex exhibited nearly monochromatic red emission at 612 nm, a remarkable luminescence quantum yield at room temperature (36.0%) upon ligand excitation and a long 5D0 lifetime (458 μs), which indicated that the ligand phenNO2 could sensitize the luminescence of Eu(III) ion efficiently.     

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(NO3)3L]*H2O (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.     

Specific features of Eu~(3+) and Tb~(3+) magnetooptics in gadolinium-gallium garnet (Gd_3Ga_5O_(12))

We reported magnetooptical properties of Eu3+(4f(6)) and Tb3+(4f(8)) in single crystals of Gd3Ga5O12 (GGG), Y3Ga5O12 (YGG), and Eu3+(4f(6)) in Eu3Ga5O12 (EuGG) for both ions occupying sites of D2 symmetry in the garnet structure. Absorption, luminescence, and magnetic circular polarization of luminescence (MCPL) spectra of Tb3+ in GGG and YGG and absorption and magnetic circular dichroism (MCD) of Eu3+ in EuGG were studied. The data were obtained at 85 K and room temperature (RT). Magnetic susceptibility of...     

Spectral analysis in ultraweak emissions of chemi- and electrochemiluminescence systems

Investigation of ultraweak emissions in the processes of chemiluminescence, CL, and electrochemiluminesce, ECL, requires special techniques of their recording and spectral analysis. From among the hitherto proposed methods of detection of the emission spectra of these processes, that of the cut-off filter was most sensitive. The usefulness of this method in interpretation of the CL and ECL systems of the quantum yields in the range 1×10⁻⁹−1×10⁻¹¹ containing ions and complexes of Eu(III), Tb(III) and Dy(III) was shown. Exceptional character of the emission bands of lanthanide ions, being a result of the f-f electron transitions and in particular their low FWHM, permitted the application of the cut-off filter method to their analysis. The results obtained for CL and ECL on the basis of analysis of ultraweak emission proved to be successful in analytical applications. The systems containing Eu(III) ions hydrated or complexed with organic ligands enabled inferring changes in the coordination sphere of the ions.     

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

Ｔｈｅｒｅｈａｓｂｅｅｎａｇｒｏｗｉｎｇｉｎｔｅｒｅｓｔｉｎｔｈｅｌｕｍｉｎｅｓｃｅｎｃｅｐｒｏｐｅｒｔｉｅｓｏｆｌａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘ ｅｓｗｉｔｈｏｒｇａｎｉｃａｃｉｄｓ ,ｓｕｃｈａｓａｒｏｍａｔｉｃａｃｉｄｓｏｒｐｈｔｈａｌｉｃａｃｉｄｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌｃｈｅｍｉｃａｌａｎｄｂｉｏｌｏｇｉｃａｌａｐｐｌｉｃａｔｉｏｎｆｏｒｐｒｏｂｅｓａｎｄｌａｂｅｌｓ .Ｅｕ3 + ａｎｄＴｂ3 + ｈａｖｅｍｏｒｅｅｘｃｅｌ ｌｅｎｔｌｕｍｉｎｅｓｃｅｎｃｅｐｒｏｐｅｒｔｉ…     

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 Tb0.5RE0.5(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.     

Luminescence study of europium（Ⅲ） tris（β-diketonato）/phosphonate complexes in chloroform

The extraction of Eu（Ⅲ） with β-diketone, HA, and monodentate or bidentate Lewis bases, B, into chloroform and the luminescence properties of the extracted species were studied. Pivaloyltrifluoroacetone, Hpta, and 2-thenoyltfifluoroacetone, Htta, were used as the β-diketones. The Lewis bases, B, were tetraethyl methylene diphosphonate, POPO, which was bidentate, and diethyl benzylphosphonate, PhPO which was monodentate. Based on the extraction data, the stability constants, log β, of the first complexes between tfis（β-diketonato）Eu（Ⅲ） and the phosphonate, EuA3B, were determined to be 6.0 for the POPO complex and 3.40 for the PhPO complex. The Eu（Ⅲ） luminescence intensity in the EuA3POPO was larger than EuA3 where A was either pta or tta at similar concentrations of Eu（Ⅲ）, while that in Eu（pta）3PhPO was stronger than EuA3; however, in Eu（tta）3PhPO, it was weaker than Eu（tta）3. The POPO functions as a sensitizer, and the PhPO functions as a quencher for the tta chelate and as a sensitizer for the pta chelate. From the lifetime and quantum yield, φ, of the Eu（Ⅲ） luminescence in the complexes as well as the observation of the extractability of Eu（Ⅲ） with the Hpta and the phosphonates and of the luminescence spectra of the complexes, it was confirmed that the extraction of Eu（Ⅲ） was remarkably enhanced with a β-diketonate and a strong Lewis base, and also the ternary complex that was formed as the extracted species, showed luminescence enhancement. This phenomenon may be due the formation of a strong bond between the Eu（Ⅲ） and the strong Lewis base leading to more hydrophobicity in the extracted species and also to more effective energy transfer from the Lewis base to the Eu（Ⅲ）. It was not significant whether the donor atoms were N or O.     

Eu(bpy)2(NO3)3(H2O)2/Nafion修饰于金电极上的电化学发光性质研究

本文合成了铕-联吡啶的二元配合物Eu(bpy)2(NO3)3(H2O)2,用元素分析、红外及紫外光谱对配合物进行了表征.采用循环伏安法,研究了用Nafion将Eu(bpy)2(NO3)3(H2O)2修饰于金电极上的电化学发光行为.讨论了介质、pH对该体系电化学发光性质的影响,推测了Eu(bpy)2(NO3)3(H2O)2电化学发光的机理.结果表明:在没有共反应试剂存在的条件下,Eu(bpy)2(NO3)3(H2O)2在pH 8.0的硼砂缓冲溶液中可以产生较强的电化学发光,其发光体可能为Eu*(bpy)2(NO3)3(H2O)2.     

Physico-chemical properties of 3-methoxy-2-nitrobenzoates of some rare earth elements（Ⅲ）

The complexes of 3-methoxy-2-nitrobenzoates of Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Er(III) and Tm(III) with the formula: Ln(C8H6NO5)3·2H2O, where Ln=lanthanides(III), were synthesized and characterized by elemental analysis, Forier transform irtrared (FTIR) spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction (XRD) measurements. The complexes had col- ours typical for Ln(III) ions. The carboxylate groups bound as bidentate chelating. On heating to 1173 K in air they decomposed in the same way, at first, dehydrated in one step to anhydrous salts, and then decomposed to the oxides of respective metals with intermediate formation of the oxycarbonates. The enthalpy values of the dehydration process changed from 133.72 to 44.50 kJ/mol. Their solubility in water at 293 K was of the order of 10-4 mol/dm3. The magnetic moments of analysed complexes were determined by Gouy’s method in the range of 76-303 K.     

复合熔盐法合成Y2O3.Eu3+红色荧光粉

以草酸钇铕(Y2(C2O4)3:Eu3+)为前驱体,采用复合熔盐(NaCl+S+Na2CO3)协助焙烧法合成Y2O3:E.u3+红色荧光粉.利用XRD、SEM、光谱分析等测试和分析荧光粉粒径、颗粒形貌以及发光性能.主要考察复合熔盐配比、用量以及焙烧温度和时间对Y2O3:Eu3+荧光粉发光性能的影响.结果表明,NaCl在...     

Synthesis, characterization and fluorescence of N,N'-BIS (6-metyl-2-pyridine-carboxylamide-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.