A competitive indirect time-resolved fluoroimmunoassay(TRFIA) was developed for detection of zearalenone(ZEN) in cereals,in which ZEN conjugated to bovine serum albumin(BSA) is used as solid-phase antigen.A competitiv...A competitive indirect time-resolved fluoroimmunoassay(TRFIA) was developed for detection of zearalenone(ZEN) in cereals,in which ZEN conjugated to bovine serum albumin(BSA) is used as solid-phase antigen.A competitive indirect TRFIA was conducted by simultaneously incubating ZEN in standard or extracted samples with anti-ZEN monoclonal antibody over ZEN-BSA coated plates,and then determining the bound ZEN monoclonal antibody with goat anti-mouse europium conjugate.Samples were extracted with methanol/water(70:30,v/v),then was subject directly for TRFIA without any clean-up procedure.The sensitivity of this method was 0.2 ng/ml.The measuring range of the ZEN-TRFIA was 0.2-200 ng/ml.The mean within-assay and between-assay coefficients variation of standard curve were both less than 10%.The recoveries of spiked cereals samples ranged from 76%-132%.10 corn and 6 wheat corn samples were tested,ZEN values obtained by this method agreed well with those obtained by commercial ELISA kit.It was concluded that this new method is suitable for rapid screening of ZEN in corn and wheat.展开更多
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 indic...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.展开更多
A new europium(III)complex Eu(C_(14)H_9O_3)_2(C_(12)H_8N_2)_2(NO_3)has been synthesized with 2-benzoylbenzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group ...A new europium(III)complex Eu(C_(14)H_9O_3)_2(C_(12)H_8N_2)_2(NO_3)has been synthesized with 2-benzoylbenzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P2_1/c,a=9.6733(6),b=22.9521(14),c=19.7701(12)?,β=94.9800(10)o,V=4372.8(5)?~3,D_c=1.557 g/cm^3,Z=4,μ(Mo Kα)=1.501 mm^(-1),F(000)=2064,the final R=0.0214 and w R=0.0510.The Eu(III)ion is coordinated by ten atoms to give a bicapped square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu^(3+):~5D_0→~7F_1(594 nm)and ~5D_0→~7F_2(618 nm).In addition,its X_(m )T decreases from 1.29767 cm^3?mol^(-1)?K at 300 K to 0.01531 cm^3?mol^(-1)?K at 2 K.展开更多
A new complex of {[Eu2(2-BrBA)6(2,2'-bpy)2]2·CH3CH2OH·H2O} (2-BrBA=2-bromobenzoate; 2,2'-bpy=2,2'-bipyridine) was prepared by solvent method and characterized with X-ray single-crystal diffractio...A new complex of {[Eu2(2-BrBA)6(2,2'-bpy)2]2·CH3CH2OH·H2O} (2-BrBA=2-bromobenzoate; 2,2'-bpy=2,2'-bipyridine) was prepared by solvent method and characterized with X-ray single-crystal diffraction, IR spectroscopy, UV spectroscopy, and fluorescence spectroscopy. The complex crystallized in triclinic crystal system, Pī space group, with a=1.17196(4) nm, b=2.36142(9) nm, c=2.59151(9) nm, α=113.266(2)°, β=101.100(2)°, and γ=94.400(2)°. Two independent dinuclear molecules were contained in the asymmetric unit. The two molecules were similar to each other. Each Eu(Ⅲ) ion was nine-coordinated with seven oxygen atoms from five 2-BrBA ligands and two nitrogen atoms from 2,2'-bpy molecule. The carboxylate groups acted as bidentate-chelating, bidentate-bridging and chelating-bridging coordination modes. The complex adopted a distorted monocapped square-antiprism coordination geometry. Five peaks at 579, 591, 613, 652, and 697 nm appeared in the fluorescence spectrum, corresponding to 5D0→7F0, 5D0→7F1, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transition emissions of the Eu(Ⅲ) ion, respectively.展开更多
A novel binuclear europium b-diketone complex with squaric acid ligand was synthesized for the first time. Its structure was elucidated by IR, UV, and Elemental Analysis. Red light emitting diode (LED) was fabricated ...A novel binuclear europium b-diketone complex with squaric acid ligand was synthesized for the first time. Its structure was elucidated by IR, UV, and Elemental Analysis. Red light emitting diode (LED) was fabricated by using the novel europium complex as an emitting layer, tris(8-quinolinolate) aluminum (III) (Alq3) as an electron-transporting layer, N, N’-diphenyl-N, N’-(3-methylphenyl)-1,1’-biphenyl-4,4’-diamine (TPD) as a hole-transporting layer. A cell structure of indium-tin-oxide/TPD/Eu-complex/Alq3/Mg: Ag was employed. Red electroluminescence was observed at room temperature with dc bias voltage of 2 V in this cell. Red emission peaks at about 613 nm with maximum luminance of over 106 cd/m2. Compared with the EL luminance from those europium complexes reported before, one from the Eu-complex is best in the same cells.展开更多
Barium titanate nanocrystallites were synthesized by a hydrothermal technique from barium chloride and tetrabutyl titanate. Single-crystalline cubic perovskite Ba TiO_3 consisting of spherical particles with diameters...Barium titanate nanocrystallites were synthesized by a hydrothermal technique from barium chloride and tetrabutyl titanate. Single-crystalline cubic perovskite Ba TiO_3 consisting of spherical particles with diameters ranging from 10 to 30 nm was easily achieved by this route. In order to study the influence of the synthesis process on the morphology and the optical properties, barium titanate was also prepared by a solid-state reaction. In this case, only the tetragonal phase which crystallizes above 900 was observed. High-temperature X-ray diffraction measurements were performed to investigate the crystallization temperatures as well as the particle sizes via the Scherrer formula. The lattice vibrations were evidenced by infrared spectroscopy. Eu^(3+)was used as a structural probe, and the luminescence properties recorded from Ba TiO_3 :Eu^(3+)and elaborated by a solid-state reaction and hydrothermal process were compared. The reddish emission of the europium is increased by the nanometric particles.展开更多
A new europium(III)complex Eu2(C15H11O3)6(C12H8N2)2 has been synthesized with 2-(4-Methylbenzoyl)benzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P21/n...A new europium(III)complex Eu2(C15H11O3)6(C12H8N2)2 has been synthesized with 2-(4-Methylbenzoyl)benzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P21/n,a=15.1238(5),b=13.5928(4),c=22.9840(7)?,β=104.132(3) ,V=4582.0(2)?3,Dc=1.522 g/cm3,Z=4,μ(MoKα)=1.433 mm-1,F(000)=2128,the final R=0.0447 and wR=0.0826.The Eu(III)ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu3+:5D0→7F1(594 nm)and 5D0→7F2(617 nm).The complex is an antiferromagnetism system in the range of 150~300 K.Also reported in the paper is the thermal stability property of the title complex.展开更多
A new europium(III) complex Eu(L)3(Phen)2(1) with 2-benzoylbenzoic acid(HL) and 1,10-phenanthroline(Phen) as ligands has been synthesized. Crystal data for the complex are as follows: monoclinic, space group P21/c, a ...A new europium(III) complex Eu(L)3(Phen)2(1) with 2-benzoylbenzoic acid(HL) and 1,10-phenanthroline(Phen) as ligands has been synthesized. Crystal data for the complex are as follows: monoclinic, space group P21/c, a = 2.2577(4), b = 1.23484(19), c = 1.8789(3) nm, β = 94.918(3)o, V = 5.2189(14) nm^3, Dc = 1.512 g/cm^3, Z = 4, μ(Mo Kα) = 1.269 mm^(-1), F(000) = 2408, the final R = 0.0433 and w R = 0.1038. The Eu(III) ion is coordinated by nine atoms to give a single-capped square antiprism coordination geometry. 1 shows two intense fluorescence emission bands arising from the transitions of Eu^(3+): ~5D_0→~7F_1(597 nm) and ~5D_0→~7F_2(615 nm) with an excitation wavelength of 396 nm. In addition, 1 displays antiferromagnetic property at low temperature.展开更多
A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by el...A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by elemental analysis, DTA TG analysis, UV Vis, FT IR and MS spectroscopy. The chemical formula is proved to be Eu(TTA)(MPPO)(HMPPO)·(NO 3)·2H 2O. Its luminescence quantum efficiency(in acetonitrile, 26 3%) is approximately the same as that of the commonly used red emission luminescent compound, Eu(TTA) 3(TPPO) 2 (TPPO is triphenyl phosphine oxide). The new complex has comparatively long fluorescence lifetime.展开更多
Two new binuclear (europium and lanthanum) β-diketone complexes Eu0.9La0.1(TTA)3Phen and Eu0.5La0.5(TTA),Phen in which Phen is 1,10-phenanthroline, TTA is an anion of thenoyltrifluoroacetone (HTTA) were synthesized f...Two new binuclear (europium and lanthanum) β-diketone complexes Eu0.9La0.1(TTA)3Phen and Eu0.5La0.5(TTA),Phen in which Phen is 1,10-phenanthroline, TTA is an anion of thenoyltrifluoroacetone (HTTA) were synthesized for the first time. They showed intense photoluminescence (PL) and mechanoluminescence (ML), and had their maximum PL and ML spectra peaked at 6 13.5 nm with half bandwidth of 10 nm respectively. Their PL and ML intensity were obviously stronger than these from Eu(TTA)3Phen. It is considered that binuclear (europium and lanthanum) β-diketones complexes are promising ML and PL materials.展开更多
A novel inductively coupled plasma mass spectrometry method for direct determination of trace rare earth impurities in high purity europium oxide （Eu2O3） was developed. The spectral interference,matrix effect,instru...A novel inductively coupled plasma mass spectrometry method for direct determination of trace rare earth impurities in high purity europium oxide （Eu2O3） was developed. The spectral interference,matrix effect,instrument parameters fluctuation were investigated and the optimized experimental conditions were established. Under the selected conditions,the detection limits of the method are 3～7 ng·L （-1）,the RSD is varied between 2.1%～8.4%,and the percentage recovery is ranged from 90% to 113% for the analytes. The solid detection limit for gross amount of 13 rare earth impurities is 0.19 μg·g （-1） when the matrix （Eu） concentration of 0.1 mg·ml （-1） was chosen. Compared with the reported methods in the literature,this method has several attractive features: simple,small sample amount required,no internal standard and matrix matching requirements.展开更多
An isolated-core-excitation (ICE) scheme and stepwise excitation are employed to study the highly excited states of the europium atom.The bound europium spectrum with odd parity in a region of 42400-43500 cm-1 is meas...An isolated-core-excitation (ICE) scheme and stepwise excitation are employed to study the highly excited states of the europium atom.The bound europium spectrum with odd parity in a region of 42400-43500 cm-1 is measured,from which spectral information on 38 transitions,such as level position and relative intensity,can be deduced.Combined with information about excitation calibration and the error estimation process,the selection rules enable us to determine the possible values of total angular momentum J for the observed states.The autoionization spectra of atomic europium,belonging to the 4f 7 6pnl (l=0,2) configurations,are systematically investigated by using the three-step laser resonance ionization spectroscopy (RIS) approach.With the ICE scheme,all the experimental spectra of the autoionizing states have nearly symmetric profiles whose peak positions and widths can be easily obtained.A comparison between our results and those from the relevant literature shows that our work not only confirms many reported states,but also discovers 14 bound states and 16 autoionizing states.展开更多
Two crystals,[Sm(Hcpna)(cpna)·3 H2O]n(1) and [Eu(Hcpna)(cpna)·2 H2O]n(2),have been synthesized by solvothermal method based on Sm3+ and Eu3+ with multiple acid ligands5-(4-carboxyphenoxy)nicotinic acid(H2cpn...Two crystals,[Sm(Hcpna)(cpna)·3 H2O]n(1) and [Eu(Hcpna)(cpna)·2 H2O]n(2),have been synthesized by solvothermal method based on Sm3+ and Eu3+ with multiple acid ligands5-(4-carboxyphenoxy)nicotinic acid(H2cpna), and the new complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, thermogravimetric analysis and fluorescence analysis. Complex 1 exhibits a 1 D chain structure. It crystallizes in the triclinic system, space group P1 with a = 5.9738(11), b = 12.528(2), c = 18.021(4)?,α= 93.156(3)o,β=98.067(3)o,γ= 92.692(3)o, V = 1331.3(4) A3, Z = 2, S = 1.069, F(000)= 702, R = 0.0277 and wR =0.0688(I > 2σ(I)). Complex 2 shows a two-dimensional network structure, which crystallizes in monoclinic system, space group C2/c with a = 13.6733(19), b = 18.422(3), c = 10.4307(15) A,β=93.881(2)o, V= 2621.4(7) A3, Z = 4, S = 1.110, F(000)= 1372, R = 0.0302 and wR = 0.0811(I >2σ(I)). The solid-state fluorescent test results show tcomplex 1 has weaker fluorescence intensity than the ligand. However, complex 2 has excellent fluorescence properties, and can emit bright red light under the irradiation of ultraviolet lamp.展开更多
This article studies the polarization properties of the cathode reduction of Eu in the Sm-Eu-Gdchloride system by using a constant potential method.As the feed concentration,temperature,and stirringrate of the system ...This article studies the polarization properties of the cathode reduction of Eu in the Sm-Eu-Gdchloride system by using a constant potential method.As the feed concentration,temperature,and stirringrate of the system change,the system can gradually turn from chemical polarization to concentrationpolarization,and there would be a higher limiting current.As to the effects of acidity,only at a rather higherpH there will be a typical polarization property.The study can give some bases for the Eu electroreductiontechnlolgy parameter selection.展开更多
The fluorescence property of europium（Ⅲ）-doxycycline（DC） complex and the effect of reaction condition were studied. It is found that in the buffer solution of Na2B4O7-NaOH at pH 9.63 europium can react with doxyc...The fluorescence property of europium（Ⅲ）-doxycycline（DC） complex and the effect of reaction condition were studied. It is found that in the buffer solution of Na2B4O7-NaOH at pH 9.63 europium can react with doxycycline to form a complex. After intramolecular energy transfer, the system shows the characteristic fluorescence of Eu 3+. The fluorescence intensity can be enhanced again in addition of non-ionic surfactant Triton X-100 with λ ex=375 nm, λ em=617 nm. Based on this, a new method using europium ion as fluorescent probe for the determination of trace doxycycline was proposed. The fluorescence intensity is linearly related to the doxycycline concentration in the range of 2.8×10 -6～2.46×10 -5 mol·L -1 with correlation coefficient 0.9973. The detection limit was 1.35×10 -8 mol·L -1. It is applied to the determination of doxycycline in pharmaceutical preparations and in serum satisfactorily. The recovery is within the range of 93%～103%.展开更多
A novel europium complex, bi（dibenzamide） benzoate europium（Ⅲ） （Eu-DBA-B）, was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium com...A novel europium complex, bi（dibenzamide） benzoate europium（Ⅲ） （Eu-DBA-B）, was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium complex is an electroneutral complex, and it emits very strong red luminescence from （（）5D1→（）7Fj） （j=0, 1, 2, 3, 4） transitions.展开更多
Electrochemical behaviours of Europium-ferrocene derivative complex chemically modified electrodes were studied in the paper. Various factors which affect the voltammetry of the thin film modified electrodes, and the ...Electrochemical behaviours of Europium-ferrocene derivative complex chemically modified electrodes were studied in the paper. Various factors which affect the voltammetry of the thin film modified electrodes, and the charge transport process of the thin film electrode were discussed. Size of the hydrated anion (counter ion), concentration of the electrolyte, swelling property of the film in the solvent and thickness of the film have significant effects on the voltammetry of the thin film electrode. Electrochemical behaviours of europium-ferrocene derivative compelx chemically modified electrode were studied in an aqueous solution. When scan ning between 0-0.8 V (vs. SCE), experimental results indicate that the chemically modified electrode has good stability and reproducibility. The apparent rate constant of electrode reaction is deteminedd to be 6.7×10-1 s-1.展开更多
基金supported by the Innovation Fund for Technology Based Firms (06C26213201075)National High Technology Research and Development Program of China (863 Program) (2008AA102415)
文摘A competitive indirect time-resolved fluoroimmunoassay(TRFIA) was developed for detection of zearalenone(ZEN) in cereals,in which ZEN conjugated to bovine serum albumin(BSA) is used as solid-phase antigen.A competitive indirect TRFIA was conducted by simultaneously incubating ZEN in standard or extracted samples with anti-ZEN monoclonal antibody over ZEN-BSA coated plates,and then determining the bound ZEN monoclonal antibody with goat anti-mouse europium conjugate.Samples were extracted with methanol/water(70:30,v/v),then was subject directly for TRFIA without any clean-up procedure.The sensitivity of this method was 0.2 ng/ml.The measuring range of the ZEN-TRFIA was 0.2-200 ng/ml.The mean within-assay and between-assay coefficients variation of standard curve were both less than 10%.The recoveries of spiked cereals samples ranged from 76%-132%.10 corn and 6 wheat corn samples were tested,ZEN values obtained by this method agreed well with those obtained by commercial ELISA kit.It was concluded that this new method is suitable for rapid screening of ZEN in corn and wheat.
基金Project supported by the National Natural Science Foundation of China (20461002)Chunhui Plan of MOE (Z2004-2-15029)
文摘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.
基金supported by the Construct Program of the Key Discipline in Hunan Province
文摘A new europium(III)complex Eu(C_(14)H_9O_3)_2(C_(12)H_8N_2)_2(NO_3)has been synthesized with 2-benzoylbenzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P2_1/c,a=9.6733(6),b=22.9521(14),c=19.7701(12)?,β=94.9800(10)o,V=4372.8(5)?~3,D_c=1.557 g/cm^3,Z=4,μ(Mo Kα)=1.501 mm^(-1),F(000)=2064,the final R=0.0214 and w R=0.0510.The Eu(III)ion is coordinated by ten atoms to give a bicapped square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu^(3+):~5D_0→~7F_1(594 nm)and ~5D_0→~7F_2(618 nm).In addition,its X_(m )T decreases from 1.29767 cm^3?mol^(-1)?K at 300 K to 0.01531 cm^3?mol^(-1)?K at 2 K.
基金Project supported by the Natural Science Foundation of Beijing (2073022)
文摘A new complex of {[Eu2(2-BrBA)6(2,2'-bpy)2]2·CH3CH2OH·H2O} (2-BrBA=2-bromobenzoate; 2,2'-bpy=2,2'-bipyridine) was prepared by solvent method and characterized with X-ray single-crystal diffraction, IR spectroscopy, UV spectroscopy, and fluorescence spectroscopy. The complex crystallized in triclinic crystal system, Pī space group, with a=1.17196(4) nm, b=2.36142(9) nm, c=2.59151(9) nm, α=113.266(2)°, β=101.100(2)°, and γ=94.400(2)°. Two independent dinuclear molecules were contained in the asymmetric unit. The two molecules were similar to each other. Each Eu(Ⅲ) ion was nine-coordinated with seven oxygen atoms from five 2-BrBA ligands and two nitrogen atoms from 2,2'-bpy molecule. The carboxylate groups acted as bidentate-chelating, bidentate-bridging and chelating-bridging coordination modes. The complex adopted a distorted monocapped square-antiprism coordination geometry. Five peaks at 579, 591, 613, 652, and 697 nm appeared in the fluorescence spectrum, corresponding to 5D0→7F0, 5D0→7F1, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transition emissions of the Eu(Ⅲ) ion, respectively.
基金This work was supported by National Natural Science Foundation of China (29972032) and Provincial Natural Science Foundation of Hunan (00JJY2043).
文摘A novel binuclear europium b-diketone complex with squaric acid ligand was synthesized for the first time. Its structure was elucidated by IR, UV, and Elemental Analysis. Red light emitting diode (LED) was fabricated by using the novel europium complex as an emitting layer, tris(8-quinolinolate) aluminum (III) (Alq3) as an electron-transporting layer, N, N’-diphenyl-N, N’-(3-methylphenyl)-1,1’-biphenyl-4,4’-diamine (TPD) as a hole-transporting layer. A cell structure of indium-tin-oxide/TPD/Eu-complex/Alq3/Mg: Ag was employed. Red electroluminescence was observed at room temperature with dc bias voltage of 2 V in this cell. Red emission peaks at about 613 nm with maximum luminance of over 106 cd/m2. Compared with the EL luminance from those europium complexes reported before, one from the Eu-complex is best in the same cells.
基金the financial support of the SEP-CONACYT(100764&178817)SIP-IPN(20130664 and 20130665) projectsthe financial support of this work by ECOSNord/ANUIES/CONACYT program number M09P01
文摘Barium titanate nanocrystallites were synthesized by a hydrothermal technique from barium chloride and tetrabutyl titanate. Single-crystalline cubic perovskite Ba TiO_3 consisting of spherical particles with diameters ranging from 10 to 30 nm was easily achieved by this route. In order to study the influence of the synthesis process on the morphology and the optical properties, barium titanate was also prepared by a solid-state reaction. In this case, only the tetragonal phase which crystallizes above 900 was observed. High-temperature X-ray diffraction measurements were performed to investigate the crystallization temperatures as well as the particle sizes via the Scherrer formula. The lattice vibrations were evidenced by infrared spectroscopy. Eu^(3+)was used as a structural probe, and the luminescence properties recorded from Ba TiO_3 :Eu^(3+)and elaborated by a solid-state reaction and hydrothermal process were compared. The reddish emission of the europium is increased by the nanometric particles.
基金supported by the cooperative project of Hengyang Normal University with Hengyang Yile New Materials Co.,Ltd.(No.HXKJ201905)
文摘A new europium(III)complex Eu2(C15H11O3)6(C12H8N2)2 has been synthesized with 2-(4-Methylbenzoyl)benzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P21/n,a=15.1238(5),b=13.5928(4),c=22.9840(7)?,β=104.132(3) ,V=4582.0(2)?3,Dc=1.522 g/cm3,Z=4,μ(MoKα)=1.433 mm-1,F(000)=2128,the final R=0.0447 and wR=0.0826.The Eu(III)ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu3+:5D0→7F1(594 nm)and 5D0→7F2(617 nm).The complex is an antiferromagnetism system in the range of 150~300 K.Also reported in the paper is the thermal stability property of the title complex.
基金Supported by the Doctoral Scientific Research Foundation of Hengyang Normal University(16D06)the Open Fund Project of Key Laboratory of Functional Organometallic Materials of Hengyang Normal University(GN15K02)
文摘A new europium(III) complex Eu(L)3(Phen)2(1) with 2-benzoylbenzoic acid(HL) and 1,10-phenanthroline(Phen) as ligands has been synthesized. Crystal data for the complex are as follows: monoclinic, space group P21/c, a = 2.2577(4), b = 1.23484(19), c = 1.8789(3) nm, β = 94.918(3)o, V = 5.2189(14) nm^3, Dc = 1.512 g/cm^3, Z = 4, μ(Mo Kα) = 1.269 mm^(-1), F(000) = 2408, the final R = 0.0433 and w R = 0.1038. The Eu(III) ion is coordinated by nine atoms to give a single-capped square antiprism coordination geometry. 1 shows two intense fluorescence emission bands arising from the transitions of Eu^(3+): ~5D_0→~7F_1(597 nm) and ~5D_0→~7F_2(615 nm) with an excitation wavelength of 396 nm. In addition, 1 displays antiferromagnetic property at low temperature.
文摘A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by elemental analysis, DTA TG analysis, UV Vis, FT IR and MS spectroscopy. The chemical formula is proved to be Eu(TTA)(MPPO)(HMPPO)·(NO 3)·2H 2O. Its luminescence quantum efficiency(in acetonitrile, 26 3%) is approximately the same as that of the commonly used red emission luminescent compound, Eu(TTA) 3(TPPO) 2 (TPPO is triphenyl phosphine oxide). The new complex has comparatively long fluorescence lifetime.
文摘Two new binuclear (europium and lanthanum) β-diketone complexes Eu0.9La0.1(TTA)3Phen and Eu0.5La0.5(TTA),Phen in which Phen is 1,10-phenanthroline, TTA is an anion of thenoyltrifluoroacetone (HTTA) were synthesized for the first time. They showed intense photoluminescence (PL) and mechanoluminescence (ML), and had their maximum PL and ML spectra peaked at 6 13.5 nm with half bandwidth of 10 nm respectively. Their PL and ML intensity were obviously stronger than these from Eu(TTA)3Phen. It is considered that binuclear (europium and lanthanum) β-diketones complexes are promising ML and PL materials.
文摘A novel inductively coupled plasma mass spectrometry method for direct determination of trace rare earth impurities in high purity europium oxide （Eu2O3） was developed. The spectral interference,matrix effect,instrument parameters fluctuation were investigated and the optimized experimental conditions were established. Under the selected conditions,the detection limits of the method are 3～7 ng·L （-1）,the RSD is varied between 2.1%～8.4%,and the percentage recovery is ranged from 90% to 113% for the analytes. The solid detection limit for gross amount of 13 rare earth impurities is 0.19 μg·g （-1） when the matrix （Eu） concentration of 0.1 mg·ml （-1） was chosen. Compared with the reported methods in the literature,this method has several attractive features: simple,small sample amount required,no internal standard and matrix matching requirements.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10574098 and 10674102)the Natural Science Foundation of Tianjin,China (Grant No.05YFJMJC05200)
文摘An isolated-core-excitation (ICE) scheme and stepwise excitation are employed to study the highly excited states of the europium atom.The bound europium spectrum with odd parity in a region of 42400-43500 cm-1 is measured,from which spectral information on 38 transitions,such as level position and relative intensity,can be deduced.Combined with information about excitation calibration and the error estimation process,the selection rules enable us to determine the possible values of total angular momentum J for the observed states.The autoionization spectra of atomic europium,belonging to the 4f 7 6pnl (l=0,2) configurations,are systematically investigated by using the three-step laser resonance ionization spectroscopy (RIS) approach.With the ICE scheme,all the experimental spectra of the autoionizing states have nearly symmetric profiles whose peak positions and widths can be easily obtained.A comparison between our results and those from the relevant literature shows that our work not only confirms many reported states,but also discovers 14 bound states and 16 autoionizing states.
基金supported by NSFC(U1504531)University Key Scientific Research Project of Henan Province(19B150014)
文摘Two crystals,[Sm(Hcpna)(cpna)·3 H2O]n(1) and [Eu(Hcpna)(cpna)·2 H2O]n(2),have been synthesized by solvothermal method based on Sm3+ and Eu3+ with multiple acid ligands5-(4-carboxyphenoxy)nicotinic acid(H2cpna), and the new complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, thermogravimetric analysis and fluorescence analysis. Complex 1 exhibits a 1 D chain structure. It crystallizes in the triclinic system, space group P1 with a = 5.9738(11), b = 12.528(2), c = 18.021(4)?,α= 93.156(3)o,β=98.067(3)o,γ= 92.692(3)o, V = 1331.3(4) A3, Z = 2, S = 1.069, F(000)= 702, R = 0.0277 and wR =0.0688(I > 2σ(I)). Complex 2 shows a two-dimensional network structure, which crystallizes in monoclinic system, space group C2/c with a = 13.6733(19), b = 18.422(3), c = 10.4307(15) A,β=93.881(2)o, V= 2621.4(7) A3, Z = 4, S = 1.110, F(000)= 1372, R = 0.0302 and wR = 0.0811(I >2σ(I)). The solid-state fluorescent test results show tcomplex 1 has weaker fluorescence intensity than the ligand. However, complex 2 has excellent fluorescence properties, and can emit bright red light under the irradiation of ultraviolet lamp.
基金Supported by The State Key Program of Fundam ental Research( G19980 613 0 8) ,National Natural Science Foundationof China( Nos.2 99710 0 5 ,2 0 0 2 3 0 0 5 ,2 0 0 710 0 4) ,and Scientific Research Foundation for the Returned Overseas ChineseScholars( S
基金The Project Supported by the National Natural Science Foundation of China
文摘This article studies the polarization properties of the cathode reduction of Eu in the Sm-Eu-Gdchloride system by using a constant potential method.As the feed concentration,temperature,and stirringrate of the system change,the system can gradually turn from chemical polarization to concentrationpolarization,and there would be a higher limiting current.As to the effects of acidity,only at a rather higherpH there will be a typical polarization property.The study can give some bases for the Eu electroreductiontechnlolgy parameter selection.
文摘The fluorescence property of europium（Ⅲ）-doxycycline（DC） complex and the effect of reaction condition were studied. It is found that in the buffer solution of Na2B4O7-NaOH at pH 9.63 europium can react with doxycycline to form a complex. After intramolecular energy transfer, the system shows the characteristic fluorescence of Eu 3+. The fluorescence intensity can be enhanced again in addition of non-ionic surfactant Triton X-100 with λ ex=375 nm, λ em=617 nm. Based on this, a new method using europium ion as fluorescent probe for the determination of trace doxycycline was proposed. The fluorescence intensity is linearly related to the doxycycline concentration in the range of 2.8×10 -6～2.46×10 -5 mol·L -1 with correlation coefficient 0.9973. The detection limit was 1.35×10 -8 mol·L -1. It is applied to the determination of doxycycline in pharmaceutical preparations and in serum satisfactorily. The recovery is within the range of 93%～103%.
文摘A novel europium complex, bi（dibenzamide） benzoate europium（Ⅲ） （Eu-DBA-B）, was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium complex is an electroneutral complex, and it emits very strong red luminescence from （（）5D1→（）7Fj） （j=0, 1, 2, 3, 4） transitions.
文摘Electrochemical behaviours of Europium-ferrocene derivative complex chemically modified electrodes were studied in the paper. Various factors which affect the voltammetry of the thin film modified electrodes, and the charge transport process of the thin film electrode were discussed. Size of the hydrated anion (counter ion), concentration of the electrolyte, swelling property of the film in the solvent and thickness of the film have significant effects on the voltammetry of the thin film electrode. Electrochemical behaviours of europium-ferrocene derivative compelx chemically modified electrode were studied in an aqueous solution. When scan ning between 0-0.8 V (vs. SCE), experimental results indicate that the chemically modified electrode has good stability and reproducibility. The apparent rate constant of electrode reaction is deteminedd to be 6.7×10-1 s-1.
