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.     

Lanthanide amino acid Schiff base complexes： synthesis, spectroscopic characterization, physical properties and in vitro antimicrobial studies

Complexes of La(Ⅲ),Nd(Ⅲ),Gd(Ⅲ),Sm(Ⅲ),and Ce(Ⅳ) were synthesized with Schiff base [(3,5-di-tert-butyl-2-hydroxybenzyl) amino] acetic acid(H 3 L).The ligand and its complexes were synthesized and characterized based on the following analysis:elemental analyses,FAB-mass,molar conductance measurements,magnetic measurement,UV-visible,IR,and NMR spectral studies.The spectral data revealed that the ligand acted as a neutral tridentate coordinating to metal ion through ONO donor sequence.Thermal degradation studies of the ligand and its complexes showed that the previous lanthanide complexes were more thermally stable than the ligand itself.The Schiff base and its complexes were screened for their antibacterial(Escherichia coli,Staphylococcus aureus) and antifungal(Aspergillus flavus and Candida Albicans).     

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...     

Nd（Ⅲ）、Sm（Ⅲ）、Eu（Ⅲ）与邻香兰素缩邻苯二胺配合物的合成与性质

合成了稀土硝酸盐与双希夫碱邻香兰素缩邻苯二胺（以Ｌ表示）的３种新固体配合物。通过元素分析、红外光谱、紫外光谱、差热一热重、摩尔电导及Ｘ射线粉末衍射分析等手段，确定配合物的组成为（ＬｎＬ（ＮＯ３）２）ＮＯ３（Ｌｎ＝Ｎｄ、Ｓｍ、Ｅｕ）。并对其结构和某些物理化学性质进行了研究。     

Synthesis,spectroscopic characterization,DNA cleavage and antibacterial studies of a novel tridentate Schiff base and some lanthanide（III） complexes

A novel potential tridentate Schiff base was prepared by condensing equimolar quantities of 2-hydroxyacetophenone and 2-aminopyrimidine in methanol. This ligand was versatile in forming a series of complexes with lanthanide ions such as La（III）, Pr（III）, Nd（III）, Sm（III）, Gd（III）, Dy（III） and Yb（III）. The ligand and the metal complexes were characterized through elemental analysis, molar conductance, UV-Visible, IR, 1H NMR, and mass spectral studies. The spectral studies indicated that the ligand was coordinated to the metal ion in neutral tridentate fashion through the azomethine nitrogen, one of the nitrogen atoms in the pyrimidine ring and the phenolic oxygen without deprotonation. Thermal decomposition and luminescence property of lanthanum（III） complex were also examined. The X-ray diffraction patterns showed the crystalline nature of the ligand and its lanthanum（III） complex. The DNA cleavage studies of the ligand and the metal complexes were carried out and it was observed that the lanthanum（III） and neo-dymium（III） complexes cleaved the pUC19 DNA effectively. The ligand and the metal complexes were screened for their antibacte-rial activities. The metal complexes were found to be more potent bactericides than the 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…     

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 Characterization of Some Lanthanide（Ⅲ） Complexes with 4- [N-（2-methoxy benzylinine）formy1]-2, 3-dimethyl-1-phenyl-3-pyazolin-5-one

A series of seven novel lanthanide（Ⅲ ） nitrato complexes with 4-[ N-（2-methoxybenzylimine）formyl] 1-2, 3- dimethyl-1-phenyl-3-pyazolin-5-one （2mbfa）, were synthesized. These complexes were characterized by elemental analysis, molecular mass determination, conductance and magnetic moment measurements, IR, UV-visible, and ^13CNMR spectral studies, In these complexes, the Schiff base, 2mbfa, acts as neutral bidentate ligand by utilizing the carbonyl oxygen and azomethine nitrogen as donor sites. All the three nitrate ions are also coordinated unidentately with 7 coordination for the lanthanide（Ⅲ） ions with a tentative monocapped octahedral geometry for the complexes. All the seven lanthanide（Ⅲ） complexes have a general formula, [ Ln（2mbfa）：（NO3）3 ].     

Optical analysis and separation of trivalent lanthanides in deep eutectic solvents

Deep eutectic solvents(DESs) were used for luminescence measurements in quantitative analysis of trivalent lanthanide ions and as solvents for light rare earth elements(LREE) in solid-liquid separation.The spectroscopic characteristics of lanthanide chlorides LnCl_3(Ln=Eu,Tb),respectively their aquo complexes,are described in a comprehensive study that demonstrates the significant enhancement of the phosphorescence emission intensity in DESs as polar and weakly coordinating solvent.Several DESs stabilize the lanthanide ion luminescence against changes in temperature and moisture,which is advantageous compared with the use of ionic liquids.Small amounts of water lead in certain eutectic systems even to a further increase in phosphorescence emission intensity.By investigating the solubility of lanthanide sesquioxides Ln_2 O_3(Ln=La,Nd,Sm,Eu,Gd,Tb,Dy) in DESs,selectivities are identified that may be of use for the separation of LREE.     

Photoluminescence properties of dinuclear lanthanide complexes in visible and near-infrared region

Several dinuclear lanthanide complexes of Ln2(HTH)6TPPHZ (Ln=Eu, Sm, Er, Nd, Yb, Ho; TPPHZ=Tetrapyrido (3,2-a:2',3'-c:3',2"-h:2"',3'"-j) phenazine; HTH=4,5,5,6,6,6-heptafluroro-1-(2-thienyl)hexane-1,3-dione were synthesized and their photoluminescence properties were investigated. After ligand-mediated excitation, all the complexes showed the characteristic luminescence of the corresponding Ln(III) ions in the visible and NIR regions attributed to energy transfer from the ligands to the metal center. For Eu...     

Microwave assisted synthesis,spectroscopic, thermal,and antifungal studies of some lanthanide（Ⅲ） complexes with a heterocyclic bishydrazone

A bishydrazone formed by the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide（Ⅲ） chloride to form complexes of the type [Ln（HISA）2Cl3], where, Ln=La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, or Gd（Ⅲ） and HISA= [（2-hydroxybenzaldehyde）-3-isatin]bishydrazone. Both reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV visible, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carbonyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum（Ⅲ） complex were subjected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhibited its crystalline nature and that of the lanthanum（Ⅲ） complex indicated its amorphous character. The thermal decomposition behaviour of the complex, [La（HISA）2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities.     

Synthesis and spectroscopic properties of rare earth picrate complexes with a new dinaphthalenelamide

The new ligand N-benzyl-2-{2'-[(benzyl-ethyl-carbamoyl)-methoxy]-dinaphthalene-2-yloxy}-N-ethyl-acetamide (L) and its complexes of rare earth picrates were synthesized. The complexes were characterized by elemental analysis, IR, UV-vis spectra and conductivity measurements. The fluorescence properties of the europium complex in solid state and CHCl₃, ethyl acetone, acetonitrile and DMF were investigated. Under the excitation, the europium complex exhibited characteristic emissions of europium. The lowest triplet state energy level of the ligand indicated that the triplet state energy level of the ligand matched better to the resonance level of Eu(III) than Tb(III) ion.     

Synthesis, Characterization and Fluorescence of Phenylcarboxymethyl Sulfoxide Complexes with Lanthanide Nitrates

Ｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｗｉｔｈｓｕｌｆｏｘｉｄｅａｎｄａｒｏｍａｔｉｃｃａｒｂｏｘｙｌａｃｉｄｈａｖｅｂｅｅｎｗｉｄｅｌｙｓｔｕｄ ｉｅｄ[1～ 3 ] .Ｉｔｉｓｐｒｏｖｅｄｔｈａｔｔｈｅｙｂｏｔｈｈａｖｅｂｅｔ ｔｅｒｆｌｕｏｒｅｓｃｅｎｃｅｃｈａｒａｃｔｅｒ .Ｈｏｗｅｖｅｒｔｈｅａｒｏ ｍａｔｉｃｃａｒｂｏｘｙｌｏｆｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｈａｖｅｖｅｒｙｈｉｇｈｆｌｕｏｒｅｓｃｅｎｃｅｅｍｉｓｓｉｏｎｉｎｔｅｎｓｉｔｙａｎｄｓｔａｂｉｌｉｔｙ ,ｂｕｔｓｏｌｕｂｉｌｉｔｙｉ…     

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 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.     

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

Pyrimidineringsystemswhichcontainmercapto grouphaveverycloserelationshiptosulphuranalogues oftheDNAbases.Mostofthosecompoundswerere portedtobetumorinhibitors,antimycotic,antileuke mic,tuberculoatat,antithyroid,andhypoglycaemic agentsandhaveattractedinterestofmany chemists[1～6].Nigametal[6]synthesizedcorresponding4,6dimethyl5(arylazo N substitutedp sulphamyl benzeneazo)pyrimidin2thiolsbycondensationof4,6dimethylpyrimidinyl2thiolwithdifferentdiazotised bases,invitroalltheobtainedthiolcompounds…     

Photoluminescence and electrochemiluminescence studies of chosen rare earths systems

Eu（Ⅲ） complexes with chosen Keggin polyoxomatalates, POM, containing organic counter cations （tetrabutylarnmonium, tetrabutylphosphonium, triphenylethylphosphonium）, were synthesized, and their photophysical properties were studied. The synthesized complexes had the general formula of XnH5-n[EuSiW11O39], formulated based on the results of elemental and thermogravimetric analysis and FTIR spectroscopy. The photophysical properties of the obtained compounds were investigated using photoluminescence and electrochemiluminescence, ECL, methods in solutions and solids. The most intense luminescence of Eu（Ⅲ） was observed for the complexes with tetrabutylarnmonium cations. After the addition of phenanthroline to the XnH5-n[EuSiW11O39] solutions, a large increase in the Eu（Ⅲ） luminescence intensity and a lengthening of its luminescence lifetime were observed as a result of the formation of ternary complexes. Attempts to apply ECL as a method of light emission by generating species capable of forming excited states in Ln/POMs, i.e., Tb（Ⅲ） and Eu（Ⅲ） in the Na9EuW10O36 and Na9TbW10O36 complexes, were made. The influence of the POM complexes on the ECL was also tested using the Tb/EDDHA （EDDA=ethylenediamine di（o-hydroxyphenylacetic acid）） complex, which is effective in generating ECL.     

Synthesis, characterization and properties of some rare earth complexes with 2,6-pyridine dicarboxylic acid and α-Picolinic acid

Five novel ternary complexes were synthesized by the rare earth with 2,6-pyridine dicarboxylic acid andα-picolinic acid.These complexes were characterized by elemental analysis,molar conductivity,FT-IR,UV-Vis,Raman,TG-DTA and XRD.The general formula of the complexes was[RE(DPA)(L α )(H2O)]·2H2O(RE=Pr 3+ ,Nd 3+ ,Sm 3+ ,Eu,Er 3+ ;DPA=2,6-pyridine dicarboxylic acid;L α =α-picolinic acid). The investigation of fluorescence properties of the Eu-complex showed that the Eu(III)ion could be sensitized efficiently by the ligand to some extent.The antibacterial activity test indicated that all the five complexes exhibited antibacterial ability against Escherichia coli and Staphylococcus aureus with broad antimicrobial spectrums.     

Synthesis and spectroscopic properties of rare earth picrate complexes with a new dinaphthalenelamide

The new ligand N-benzyl-2-{2’-[(benzyl-ethyl-carbamoyl)-methoxy]-dinaphthalene-2-yloxy}-N-ethyl-acetamide(L) and its complexes of rare earth picrates were synthesized.The complexes were characterized by elemental analysis,IR,UV-vis spectra and conductivity measurements.The fluorescence properties of the europium complex in solid state and CHCl3,ethyl acetone,acetonitrile and DMF were investigated.Under the excitation,the europium complex exhibited characteristic emissions of europium.The lowest triplet state energy level of the ligand indicated that the triplet state energy level of the ligand matched better to the resonance level of Eu(Ⅲ) than Tb(Ⅲ) ion.     

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.