In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by...In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by alpha-induced reactions in detail,with a specific focus on determining the optimum production parameters and testing existing nuclear models.Given the limited number of experiments conducted on reactions related to terbium isotope production,it is necessary to perform theoretical calculations of cross sections over a wide energy range to gain a detailed understanding of terbium isotope production.To achieve this objective,the cross sections of the ^(151)Eu(α,n)^(154) Tb reactions were calculated up to 60 MeV using the TALYS computer code with 432 different combinations of optical model parameters,level density,and strength function models.The theoretical reaction cross-section results were compared with the experimental results in the literature.The best input parameters were determined using the Threshold Logic Unit method,and these parameters were used in all isotope production calculations.Once the optimal model combination was determined,the total activity production and isotopic fraction of ^(152) Tb and ^(155) Tb isotopes were calculated in detail for beam energies of 17–50 MeV,different irradiation times,and varying ^(151) Eu and ^(153) Eu target thicknesses.展开更多
Herein,we reported a Tb-carboxyl-imidazole coordination-crosslinked carboxylated nitrile butadiene rubber(XNBR)elastomer design that exhibits high mechanical robustness,fluorochromism,and white-light emission.Imidazol...Herein,we reported a Tb-carboxyl-imidazole coordination-crosslinked carboxylated nitrile butadiene rubber(XNBR)elastomer design that exhibits high mechanical robustness,fluorochromism,and white-light emission.Imidazole(Im),a toughening,sensitizing,and self-emissive ligand,highly intensified the fluorescence emission,remarkably toughened the elastomer,and imparted multistimuli responsiveness to the elastomer.The Tb^(3+)ions acted as cross-linking centers and provided high-temperature sensitivity of fluorescence emission(more sensitive than Eu^(3+)ions).The as-prepared XNBR/Tb/Im elastomer,with excellent puncture resistance,exhibited an ultimate extensibility of about 3100%and the highest tensile strength of 22 MPa.Experimental and theoretical investigations have demonstrated that Tb^(3+)ions are more likely to interact with Im ligands with increasing amounts of Im.The number of coordination cross-links with higher cross-linking functionalities showed an increasing trend during stretching.The elastomer exhibited an excitation wavelength and temperature-dependent green emission.By introducing redemissive Eu^(3+)into the elastomer,a white-light-emitting XNBR/Tb/Eu/Im elastomer with chemo-fluorochromism was fabricated.The XNBR/Tb/Eu/Im elastomer exhibited stable white-light emission during both heating and stretching.Changing the temperature only resulted in a variation in the intensity of the white light.We demonstrated the potential applications of these elastomers in patterning and information anticounterfeiting/encryption.This coordination crosslinked tough elastomer with fluorochromism and white-light emission paves a new way to fabricate soft devices and sensors,where optical information displays and optical signal responses are required.展开更多
The phenomenon of fluorescence enhancement for the system of terbium(b!) with terephthalic acid (benzene-1,4-dicarboxylic acid (TPA)) in the presence of an excess of La3+ in Triton X-100 aqueous solution has been stud...The phenomenon of fluorescence enhancement for the system of terbium(b!) with terephthalic acid (benzene-1,4-dicarboxylic acid (TPA)) in the presence of an excess of La3+ in Triton X-100 aqueous solution has been studied. The fluorescence intensity of Tbb!-TPA system can be greatly increased by La3+. The intermolecular transfer of energy was responsible for the mechanism of the fluorescence enhancement. Triton X-100 plays an important role for the stabilization of the system. The system, having the maximum excitation and emission wavelengths at 256 nm and 546 nm, respectively, shows a constant fluorescence intensity over the pH range between 4-6. The fluorescence intensity is a linear function of Tb3+concentration in the range of 1.00 ?展开更多
A reactive Tb（III） complex with 2-aminobenzoic acid（2-ABAH） and acrylonitrile（AN） as ligands was synthesized.The structure of the complex was characterized by elemental analysis and Fourier transform infrared sp...A reactive Tb（III） complex with 2-aminobenzoic acid（2-ABAH） and acrylonitrile（AN） as ligands was synthesized.The structure of the complex was characterized by elemental analysis and Fourier transform infrared spectrometry（FT-IR）.The results indicated that the ligands were coordinated with Tb（III） ion.Thermal gravity-derivative thermogravimetric（TG-DTG） analysis indicated that the complex kept stable up to 198 oC.Luminescence properties were investigated by UV-vis absorption spectra and fluorescence spectra.The results suggested that being excited at 361 nm,the complex exhibited characteristic emission of Tb（III） ion,revealing that the complex could be excited by 365 nm ultraviolet chip.The HOMO and LUMO,ΔE（HOMO-LUMO）,molecular frontier orbital,and the singlet state and triplet energy state levels of the ligands were calculated at the B3LYP/6-31＋G（d） level.The results indicated that intramolecular energy transfer mechanism followed Dexter exchange energy transfer theory.Both the calculation for excited state of ligand and energy transfer mechanism could provide the theoretical basis for the design of high luminescent materials of rare earth complexes with organic ligands.展开更多
The formation behaviors of terbium sesquisulfide(Tb_2S_3)and holmium sesquisulfide(Ho_2S_3)synthesized via the sulfurization of their oxide powders using CS_2 gas in the range of temperature 673 to 1323 K were investi...The formation behaviors of terbium sesquisulfide(Tb_2S_3)and holmium sesquisulfide(Ho_2S_3)synthesized via the sulfurization of their oxide powders using CS_2 gas in the range of temperature 673 to 1323 K were investigated. In the sulfurization of Tb_4O_7 powder, Tb_2O_3 and Tb_2O_2S were formed in the initial stage of reaction, and α-Tb_2S_3 was finally formed at higher temperature. For long sulfurization time of 8 h, single-phase α-Tb_2S_3 could be synthesized at 1323 K. In the sulfurization of Ho_2O_3 powder using CS_2 gas, only Ho_2O_2S was formed as an intermediate product. At a sulfurization temperature above 873 K, Ho_2O_2S was formed in the initial stage of reaction, and single-phase δ-Ho_2S_3 was formed at 1323 K for 8 h instead of Ho_2O_2S. Furthermore, the influence of the addition of carbon black to the sulfurization of Ho_2O_3 powder using CS_2 gas was investigated, and the result implied that the reactions were accelerated slightly by the addition of carbon black.展开更多
The fluorescence of terbium （Ⅲ） was enhanced by about three orders of magnitude in the presence of trimellitic acid （benzene-1, 2, 4-tricarboxylic acid （TLA）） in aqueous solution at pH 6. The fluorescence inten...The fluorescence of terbium （Ⅲ） was enhanced by about three orders of magnitude in the presence of trimellitic acid （benzene-1, 2, 4-tricarboxylic acid （TLA）） in aqueous solution at pH 6. The fluorescence intensity could be greatly increased when the system of Tb^3＋-TLA was treated with La^3＋ （or Gd^3＋） and TritonX- 100. The addition of La^3＋ （or Gd^3＋） enhanees the fluorescence of the system by about two orders of magnitude due to cofluorescenee, and the TritonX-100 micellar medium plays an important role for stabilization of the system. Both the intermolecular energy transfer mode and intramolecular energy transfer mode are responsible for the mechanism of fluorescence enhancement. In the optimum condi- tions, the fluorescence intensity is a linear function of Tb3~ concentration in the range of 7.8 × 10^-9-3.6 × 10^4 mol/L for the system Tb^3＋-La^3＋-TLA and 1.0 × 10^-8-4.7 × 10^-5 mol/L for the system Tb^3＋-Gd^3＋-TLA, and the limits of detection are 4.6 × 10^-10 mol/L and 6.0 × 10^-10 mol/L, respectively.展开更多
A terbium benzoate complex with 1,10-phenanthroline [Tb(ba)3(phen)]2, where ba = benzoate and phen = 1,10-phenanthroline, has been prepared and structurally characterized by X-ray diffraction. It crystallizes in tri...A terbium benzoate complex with 1,10-phenanthroline [Tb(ba)3(phen)]2, where ba = benzoate and phen = 1,10-phenanthroline, has been prepared and structurally characterized by X-ray diffraction. It crystallizes in triclinic, space group P1 with a = 10.7881(5), b = 11.9262(6), c = 12.4249(6) ?, a = 105.1260(10), β = 93.6010(10), ? = 113.3350(10)o, (C33H23N2O6Tb)2, Mr = 1404.90, V = 1391.87(12) ?3, Z = 1, Dc = 1.676 g/cm3, μ(MoKα) = 2.590 mm-1, F(000) = 696, the final R = 0.0277 and wR = 0.0670 for 6085 observed reflections with I > 2σ(I). The crystal consists of binuclear molecules of the title compound. Each Tb3+ ion is nine-coordinated to one 1,10-phenan- throline molecule, one bidentate carboxylate group and four bridging carboxylate groups. The carboxylate groups are bonded to the terbium ion in three modes: the chelating bidentate, bridging bidentate and bridging-chelating tridentates. Excitation and luminescence data observed at room temperature show that the title complex emits very intensive green fluorescence under ultraviolet light. The results of thermal analysis indicate that the complex [Tb(ba)3phen]2 is very thermal stable.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 Tb0.5 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.展开更多
The distribution rules of impurities in distilled terbium metal were investigated by vacuum distillation purificationexperiment and theoretical analysis.It is found that Ti impurity in distilled terbium is220mg/kg in ...The distribution rules of impurities in distilled terbium metal were investigated by vacuum distillation purificationexperiment and theoretical analysis.It is found that Ti impurity in distilled terbium is220mg/kg in the initial stage of the distillationpurification,increases slowly in the middle stage,and increases rapidly in the last stage,reaching2260mg/kg,and the modifiedseparation coefficient of Ti is1/19.02.The diffusion of the impurity Ti in liquid metal can reach a quasi-equilibrium state in theinitial stage of distillation purification and the calculated results agree well with experimental results;the distribution profile ofimpurity Cu is opposite to Ti,being380mg/kg in the initial stage,decreasing linearly to290mg/kg in the last stage,and themodified separation coefficient is17.99,and the theoretical calculated results are inconsistent with the experimental result.展开更多
Abstract： Ten solid terbium complexes with 2-pyrazinecarboxylic acid （Hpyca） and butanedioic acid （BDAH） were synthesized via coprecipitation method and characterized by elemental, EDTA titration, inductively cou...Abstract： Ten solid terbium complexes with 2-pyrazinecarboxylic acid （Hpyca） and butanedioic acid （BDAH） were synthesized via coprecipitation method and characterized by elemental, EDTA titration, inductively coupled plasma （ICP）, thermogravim- etry-differential scanning calorimetry （TG-DSC） and infrared （IR） analyses. The results showed that the complexes had the composi- tions of Tb（pyca）（BDA）·2H2O, Tb0.5Y0.5（pyca）（BDA）·2H2O, Tb0.5La0.5（pyca）（BDA）·3H20, Tb0.5Gd0.5（pyca）（BDA）·2H2O, Tb0.7Y0.3（pyca）（BDA）·3HO, Tb0.7Lao.3（pyca）（BDA）-0.5H20, Tb0.TGd0.3（pyea）（BDA）＇H20, Tb0.6Y0.4（pyca）（BDA）·2.5H20, Tb0.6La0.4 （pyca）（BDA）·2.5H2O and Tbo.6Gd0.4（pyca）（BDA）·3H20. IR spectra indicated that the rare earth ions coordinated with the carboxylic oxygen atoms of Hpyca and BDAH. Luminescence spectra showed that the doped La3＋, y3＋ or Gd3＋ ions did not affect the lumines- cence emission peak positions, but remarkably increased the luminescent intensities of terbium complexes. Furthermore, the doped lanthanide complexes showed longer luminescence lifetimes and higher quantum yields than pure terbium complex. The enhanced luminescence efficiencies of Tb3＋ ions in the doped complexes might result from the antenna effect of the two carboxylate ligands as well as the decrease of the self-quench of the Tb3＋ ions induced by the doped lanthanide ions.展开更多
The effect of an anionic surfactant (sodium dodecyl sulfate, SDS) on the fluorescence properties of nucleic acid with terbium (III) is studied. Results show that ribonucleic acid (RNA) presents fluorescence reaction w...The effect of an anionic surfactant (sodium dodecyl sulfate, SDS) on the fluorescence properties of nucleic acid with terbium (III) is studied. Results show that ribonucleic acid (RNA) presents fluorescence reaction with Tb (III) directly, but deoxyribonucleic acid (DNA) presents similar fluorescence reaction only after its denaturation. In the presence of SDS, the fluorescence intensity is 4.0 times and 3.5 times greater than that of DNA and RNA without SDS.展开更多
The effect of mechanical activation （MA） on the kinetics of terbium （Tb） leaching from waste phosphors using hydrochloric acid was investigated. Leaching kinetics, such as apparent reaction rate, activation energy...The effect of mechanical activation （MA） on the kinetics of terbium （Tb） leaching from waste phosphors using hydrochloric acid was investigated. Leaching kinetics, such as apparent reaction rate, activation energy and reaction order, were determined using the shrinking-core model and the Arrhenius equation. Results obtained from experiments with different concentrations of HC1 and under different leaching temperatures were used for the determinations. The impacts of factors such as rotational speed, HC1 concen- tration and leaching temperature on the leaching rate of Tb were also discussed. The results showed that MA could dramatically increase the leaching rate of Tb from waste phosphors, and the apparent reaction rate （kap） of leaching was accelerated as well. For inactivated waste phosphors, the apparent activation energy （Eap） was 52.82±3.95 kJ/mol, indicating that the rate-controlling step of the leaching process was the chemical reaction. The Eap dropped to 25.96 ±3.90 kJ/mol and 10.96±2.79 k J/tool when the waste phosphors were mechanically activated at rotational speeds of 400 and 600 r/min, respectively; the leaching process transformed to a hybrid （chemical-reaction and diffusion） control process, and even a reagent-diffusion （through the product layer） control process. The apparent reaction order for Tb leaching from 400 r/min-activated waste phosphors was 2.49±0.11, and it decreased to 1. 16±0.17 when the rotational speed of 600 r/min was used. Kinetics results indicated that MA could make Tb leaching occur spontaneously, and thc activation intensity of waste phosphors was strengthened with higher rotational speed.展开更多
A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by...A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by X-ray diffraction. The crystal of the complexTb(o-MBA)_3phen belongs to triclinic crystal system and P1 (#2) space group. The crystal data are asfollows: a = 1.4371(4) nm, b = 1.7387(2) nm, c = 1.3109(2) nm, α = 96.37(1)°, β = 107.21(2)°,γ= 82.78(2)°, Ⅴ= 3.094(1) nm^3, Z= 2, M_r = 1489.12, D_c= 1.598 g·cm^(-3), μ = 2.330 mm^(-1)and F(000) = 1488.00. The final R and R_w are 0.038 and 0.047 for 8668 [Ⅰ > 2σ(Ⅰ)] uniquereflections, respectively. In the complex each Tb^(3+) ion is eight-coordinated by one1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups.The carboxylate groups are bonded to the terbium ion in two modes: the chelating bidentate and thebridging bidentate. Excitation and luminescence data observed at room temperature show that thetitle complex emits strong green fluorescence under ultraviolet light. The results of thermalanalysis indicate that the complex Tb(o-MBA)_3phen is quite stable to heat.展开更多
Fluorescence characteristics of complex system of rare earth terbium （Tb3＋）, norfloxacin, 1,10-phenanthroline（1,10-phen） and sur- factant sodium dodecyl benzene sulfonate （SDBS） had been studied by using fluore...Fluorescence characteristics of complex system of rare earth terbium （Tb3＋）, norfloxacin, 1,10-phenanthroline（1,10-phen） and sur- factant sodium dodecyl benzene sulfonate （SDBS） had been studied by using fluorescence spectroscopy. In a buffer solution （pH=6.3）, the fluorescence intensity of the norfloxacin-Tb3＋ （NFLX-Tb3＋） system had been remarkably enhanced by SDBS and 1,10-Phen. When excited at 335 nm, a good linear relationship between fluorescence intensity of NFLX-Tb3＋ system and NFLX concentration was obtained in the range of 8× 10-8-4× 10-6 mol/L, and the linear equation was F=2× 10^8 CNFLX＋22.7 with correlation coefficient of 0.9959. In addition, this method was compared with some previous literatures, the proposed method had relatively higher sensitivity and lower detect limit. The method was sim- ple, rapid, sensitive, practical and suitable for direct analysis of pharmaceutical preparation. It was successfully applied to determine the cap- sules, human serum and urine in real pharmaceutical samples.展开更多
The binding of Tb 3+ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb 3+ at 549 nm. The conditional equilibrium constants for the complexation of Tb 3+ by chicken apoovotransferri...The binding of Tb 3+ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb 3+ at 549 nm. The conditional equilibrium constants for the complexation of Tb 3+ by chicken apoovotransferrin in 0 1 mol/L hepes, at pH 7 4 and room temperature were measured. The successive macroscopic binding constants are lg K 1=9 08±0 12 and lg K 2=7 36±0 22. The molar fluorescence enhancement of Tb 3+ apoovotransferrin complex is (2 06±0 14)×10 4 mol -1 ·L. The fluorescence quenching experiment and the titration of N terminal monoferric ovotransferrin showed that Tb 3+ has a preference for being bound to the N terminal binding site of apoovotransferrin.展开更多
The phenomenon of fluorescence enhancement for the system of terbium( Ⅲ ) with trimesic acid [ ben-zene-1, 3, 5-tricarboxylic acid (TMA)] in the presence of an excase of La￣(3+) in gelatin aqusous solution wasstudi...The phenomenon of fluorescence enhancement for the system of terbium( Ⅲ ) with trimesic acid [ ben-zene-1, 3, 5-tricarboxylic acid (TMA)] in the presence of an excase of La￣(3+) in gelatin aqusous solution wasstudied. The fluorescence intensity of Tb￣Ⅲ -TMA system can be greatly increased by La￣(3+) , which causedthe largest enhancement of the fluorescence intensity over two orders of magnitude. The intermolecular transfer of energy was responsible for the mechanism of the fluorascence enhancement. Gelatin plays animportant role for the stabilization of the system. The system, having the maximum excitation and emis-sion wavelengths at 260 nm and 549 nm, respectively, shows a constant fluorescence interisity over the pHrange 4～6. The fluorescence intensity is a linear function of Tb￣(3+) concentration in the range of 8. 0 ×10 ￣(-9)～ 2. 6 × 10￣(-7) mol· L￣(-1) and the limit of detection is 2.0 × 10￣(-9) mol·L￣(-1) . The optimized procedurewas used for the determination of trace amount of terbium in rare earth oxides and international standardreference rocks with satisfactory results.展开更多
Poly (N-vinylacetatnide) ( PNVA) was synthesized by free radical polymerization in ethanol solution, in which alpha, alpha'-azobisisobutyronitrile was used as an initiator. Tb(III)-PNVA polymer was prepared and ch...Poly (N-vinylacetatnide) ( PNVA) was synthesized by free radical polymerization in ethanol solution, in which alpha, alpha'-azobisisobutyronitrile was used as an initiator. Tb(III)-PNVA polymer was prepared and characterized by ultraviolet-visual (UV), fourier transform infrared (FIF-IR), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. The experimental results of UV, FT-IR and XPS show that the Tb (III)-PNVA electrovalent complex is formed by electrostatic interaction between terbium (III) cation and complexible atoms of acylamino group in the pendant chain of the polymer. The fluorescence spectrum of the complex exhibits intensive characteristic emission of terbium at 490, 545 and 584 run, which are assigned to D-5(4)->F-7(6), D-5(6)->F-5(6) and D-5(4)->F-7(3) transition, indicating that there exists an efficient intermolecular energy transfer from the polymer ligand to the central rare earth ion. The emission intensity of the complex is increased with the increasing concentration of Tb (III) ion until the weight ratio of Tb (III) on to PNVA is 1.5% (mass fraction), and decreased with the further increasing concentration of Tb (III) ion, which is a typical concentration quenching behavior.展开更多
By modifying the salicylic-acid moiety with electron-withdrawing or –donating groups, three new terbium complexes（LⅠ·Tb, LⅡ·Tb, L·（Ⅲ）Tb） based on tripodal carboxylate ligands were synthesized. D...By modifying the salicylic-acid moiety with electron-withdrawing or –donating groups, three new terbium complexes（LⅠ·Tb, LⅡ·Tb, L·（Ⅲ）Tb） based on tripodal carboxylate ligands were synthesized. Due to different pull-push electronic effects of ligands, the fluorescence intensities of these terbium complexes significantly varied, that is： LⅡ·Tb 〉L（Ⅲ）·Tb〉 LⅠ·Tb. Meanwhile, the characteristic peaks at 492 nm（5D4→7F6） and 547 nm（5 D4→7F5） showed ＂Off–On–Off＂ fluorescence response to various p H conditions,which indicated that all of them can be used as the highly sensitive pH fluorescent probes. Notably, using LⅡ·Tb with the best fluorescence performance as a probe, some patients＇ urine samples can be easily monitored through the response triggered by pH value. Therefore, LⅡ·Tb has the potential to auxiliarily diagnose some diseases in clinical practice through p H detection of routine urine test.展开更多
A novel terbium-mercury complex [Tb(IA)3(H3 O)2]2 n(2 n HgCl4)(n Hg2 Cl5)·n H3 O· 3 n H2 O(1, HIA = isonicotinic acid) has been synthesized through hydrothermal reactions and characterized by single-crystal ...A novel terbium-mercury complex [Tb(IA)3(H3 O)2]2 n(2 n HgCl4)(n Hg2 Cl5)·n H3 O· 3 n H2 O(1, HIA = isonicotinic acid) has been synthesized through hydrothermal reactions and characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in the C2/c space group of monoclinic system with a = 24.2347(5), b = 20.8342(6), c = 15.3206(3) ?, β = 128.257(2)°, V = 6074.3(2) ?3, C36H41Cl13Hg4N6O20Tb2, Mr = 2458.80, Z = 4, Dc = 2.689 g/cm3, μ(Mo Kα) = 13.014 mm–1 and F(000) = 4520. The crystal structure of 1 is characterized by a one-dimensional(1-D) chain-like structure. Solid-state UV/Vis diffuse reflectance spectrum reveals the existence of a wide optical band gap of 3.36 eV. Solid-state photoluminescence experiment uncovers that it shows reddish brown upconversion emission. The emission bands are originated from the characteristic emission of the 4 f electrons intrashell transition of the 5D4 → 7 FJ(J = 6, 5, 4) of the Tb3+ ions. Energy transfer mechanism is explained by the energy level diagram of the Tb3+ ion and the isonicotinic acid ligand. It shows a remarkable CIE chromaticity coordinates(0.4158, 0.4005).展开更多
We report a facile, effective and rapid screening method for the determination of total fluoroquinolones(FQs) in milk using lanthanide coordination polymer nanomaterials as the sensing platform. The nonluminescent coo...We report a facile, effective and rapid screening method for the determination of total fluoroquinolones(FQs) in milk using lanthanide coordination polymer nanomaterials as the sensing platform. The nonluminescent coordination polymer nanosheets(CPNSs) used in this work are composed of adenosine monophosphate(AMP) and terbium(Tb^(3+)) ions(AMP/Tb CPNSs). The as-prepared CPNSs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and fluorescence techniques. Tb^(3+) acts as the center ion of the coordination polymer, with AMP assembled through phosphate and amine groups. However, the reaction between FQs and AMP/Tb CPNSs noticeably turns on the fluorescence due to the strong coordination interaction between FQs and Tb^(3+). Under optimized conditions, the fluorescence intensity of AMP/Tb at 545 nm shows a linear relationship with FQ concentrations between 0.04 μmol/L and 5.0 μmol/L. The relative standard deviation(RSD) of the intraday precision is below 1%, and detection limits are as low as 0.01 μmol/L. The proposed method was successfully applied to the determination of FQs in milk samples.展开更多
文摘In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by alpha-induced reactions in detail,with a specific focus on determining the optimum production parameters and testing existing nuclear models.Given the limited number of experiments conducted on reactions related to terbium isotope production,it is necessary to perform theoretical calculations of cross sections over a wide energy range to gain a detailed understanding of terbium isotope production.To achieve this objective,the cross sections of the ^(151)Eu(α,n)^(154) Tb reactions were calculated up to 60 MeV using the TALYS computer code with 432 different combinations of optical model parameters,level density,and strength function models.The theoretical reaction cross-section results were compared with the experimental results in the literature.The best input parameters were determined using the Threshold Logic Unit method,and these parameters were used in all isotope production calculations.Once the optimal model combination was determined,the total activity production and isotopic fraction of ^(152) Tb and ^(155) Tb isotopes were calculated in detail for beam energies of 17–50 MeV,different irradiation times,and varying ^(151) Eu and ^(153) Eu target thicknesses.
基金financially supported by the National Natural Science Foundation of China(Nos.22175100 and 52173020)the Natural Science Foundation of Zhejiang Province(No.LY22E030001)the Natural Science Foundation of Ningbo(No.2022J102)。
文摘Herein,we reported a Tb-carboxyl-imidazole coordination-crosslinked carboxylated nitrile butadiene rubber(XNBR)elastomer design that exhibits high mechanical robustness,fluorochromism,and white-light emission.Imidazole(Im),a toughening,sensitizing,and self-emissive ligand,highly intensified the fluorescence emission,remarkably toughened the elastomer,and imparted multistimuli responsiveness to the elastomer.The Tb^(3+)ions acted as cross-linking centers and provided high-temperature sensitivity of fluorescence emission(more sensitive than Eu^(3+)ions).The as-prepared XNBR/Tb/Im elastomer,with excellent puncture resistance,exhibited an ultimate extensibility of about 3100%and the highest tensile strength of 22 MPa.Experimental and theoretical investigations have demonstrated that Tb^(3+)ions are more likely to interact with Im ligands with increasing amounts of Im.The number of coordination cross-links with higher cross-linking functionalities showed an increasing trend during stretching.The elastomer exhibited an excitation wavelength and temperature-dependent green emission.By introducing redemissive Eu^(3+)into the elastomer,a white-light-emitting XNBR/Tb/Eu/Im elastomer with chemo-fluorochromism was fabricated.The XNBR/Tb/Eu/Im elastomer exhibited stable white-light emission during both heating and stretching.Changing the temperature only resulted in a variation in the intensity of the white light.We demonstrated the potential applications of these elastomers in patterning and information anticounterfeiting/encryption.This coordination crosslinked tough elastomer with fluorochromism and white-light emission paves a new way to fabricate soft devices and sensors,where optical information displays and optical signal responses are required.
基金This project is financially supported by the Gansu Province Natural Science Foundation (ZR-97-21)
文摘The phenomenon of fluorescence enhancement for the system of terbium(b!) with terephthalic acid (benzene-1,4-dicarboxylic acid (TPA)) in the presence of an excess of La3+ in Triton X-100 aqueous solution has been studied. The fluorescence intensity of Tbb!-TPA system can be greatly increased by La3+. The intermolecular transfer of energy was responsible for the mechanism of the fluorescence enhancement. Triton X-100 plays an important role for the stabilization of the system. The system, having the maximum excitation and emission wavelengths at 256 nm and 546 nm, respectively, shows a constant fluorescence intensity over the pH range between 4-6. The fluorescence intensity is a linear function of Tb3+concentration in the range of 1.00 ?
基金Project supported by the Program for Changjiang Scholar and Innovative Research Team in University (IRT0972)the International Cooperation Program of Shanxi Province (2009081046)the Postgraduate Innovation Program of Shanxi Province (20103023)
文摘A reactive Tb（III） complex with 2-aminobenzoic acid（2-ABAH） and acrylonitrile（AN） as ligands was synthesized.The structure of the complex was characterized by elemental analysis and Fourier transform infrared spectrometry（FT-IR）.The results indicated that the ligands were coordinated with Tb（III） ion.Thermal gravity-derivative thermogravimetric（TG-DTG） analysis indicated that the complex kept stable up to 198 oC.Luminescence properties were investigated by UV-vis absorption spectra and fluorescence spectra.The results suggested that being excited at 361 nm,the complex exhibited characteristic emission of Tb（III） ion,revealing that the complex could be excited by 365 nm ultraviolet chip.The HOMO and LUMO,ΔE（HOMO-LUMO）,molecular frontier orbital,and the singlet state and triplet energy state levels of the ligands were calculated at the B3LYP/6-31＋G（d） level.The results indicated that intramolecular energy transfer mechanism followed Dexter exchange energy transfer theory.Both the calculation for excited state of ligand and energy transfer mechanism could provide the theoretical basis for the design of high luminescent materials of rare earth complexes with organic ligands.
文摘The formation behaviors of terbium sesquisulfide(Tb_2S_3)and holmium sesquisulfide(Ho_2S_3)synthesized via the sulfurization of their oxide powders using CS_2 gas in the range of temperature 673 to 1323 K were investigated. In the sulfurization of Tb_4O_7 powder, Tb_2O_3 and Tb_2O_2S were formed in the initial stage of reaction, and α-Tb_2S_3 was finally formed at higher temperature. For long sulfurization time of 8 h, single-phase α-Tb_2S_3 could be synthesized at 1323 K. In the sulfurization of Ho_2O_3 powder using CS_2 gas, only Ho_2O_2S was formed as an intermediate product. At a sulfurization temperature above 873 K, Ho_2O_2S was formed in the initial stage of reaction, and single-phase δ-Ho_2S_3 was formed at 1323 K for 8 h instead of Ho_2O_2S. Furthermore, the influence of the addition of carbon black to the sulfurization of Ho_2O_3 powder using CS_2 gas was investigated, and the result implied that the reactions were accelerated slightly by the addition of carbon black.
基金This work was financially supported by the Science Foundation of Hunan Province, China (No. 01C030)
文摘The fluorescence of terbium （Ⅲ） was enhanced by about three orders of magnitude in the presence of trimellitic acid （benzene-1, 2, 4-tricarboxylic acid （TLA）） in aqueous solution at pH 6. The fluorescence intensity could be greatly increased when the system of Tb^3＋-TLA was treated with La^3＋ （or Gd^3＋） and TritonX- 100. The addition of La^3＋ （or Gd^3＋） enhanees the fluorescence of the system by about two orders of magnitude due to cofluorescenee, and the TritonX-100 micellar medium plays an important role for stabilization of the system. Both the intermolecular energy transfer mode and intramolecular energy transfer mode are responsible for the mechanism of fluorescence enhancement. In the optimum condi- tions, the fluorescence intensity is a linear function of Tb3~ concentration in the range of 7.8 × 10^-9-3.6 × 10^4 mol/L for the system Tb^3＋-La^3＋-TLA and 1.0 × 10^-8-4.7 × 10^-5 mol/L for the system Tb^3＋-Gd^3＋-TLA, and the limits of detection are 4.6 × 10^-10 mol/L and 6.0 × 10^-10 mol/L, respectively.
基金This work was supported by the Natural Science Foundation of Hebei Province (No. 203148 and No. 202140)
文摘A terbium benzoate complex with 1,10-phenanthroline [Tb(ba)3(phen)]2, where ba = benzoate and phen = 1,10-phenanthroline, has been prepared and structurally characterized by X-ray diffraction. It crystallizes in triclinic, space group P1 with a = 10.7881(5), b = 11.9262(6), c = 12.4249(6) ?, a = 105.1260(10), β = 93.6010(10), ? = 113.3350(10)o, (C33H23N2O6Tb)2, Mr = 1404.90, V = 1391.87(12) ?3, Z = 1, Dc = 1.676 g/cm3, μ(MoKα) = 2.590 mm-1, F(000) = 696, the final R = 0.0277 and wR = 0.0670 for 6085 observed reflections with I > 2σ(I). The crystal consists of binuclear molecules of the title compound. Each Tb3+ ion is nine-coordinated to one 1,10-phenan- throline molecule, one bidentate carboxylate group and four bridging carboxylate groups. The carboxylate groups are bonded to the terbium ion in three modes: the chelating bidentate, bridging bidentate and bridging-chelating tridentates. Excitation and luminescence data observed at room temperature show that the title complex emits very intensive green fluorescence under ultraviolet light. The results of thermal analysis indicate that the complex [Tb(ba)3phen]2 is very thermal stable.
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 Tb0.5 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.
基金Project(51504036) supported by the National Natural Science Foundation of ChinaProject(2012CBA01207) supported by the National Basic Research Program of ChinaProject(2011AA03A409) supported by the National High-Tech Research and Development Program of China
文摘The distribution rules of impurities in distilled terbium metal were investigated by vacuum distillation purificationexperiment and theoretical analysis.It is found that Ti impurity in distilled terbium is220mg/kg in the initial stage of the distillationpurification,increases slowly in the middle stage,and increases rapidly in the last stage,reaching2260mg/kg,and the modifiedseparation coefficient of Ti is1/19.02.The diffusion of the impurity Ti in liquid metal can reach a quasi-equilibrium state in theinitial stage of distillation purification and the calculated results agree well with experimental results;the distribution profile ofimpurity Cu is opposite to Ti,being380mg/kg in the initial stage,decreasing linearly to290mg/kg in the last stage,and themodified separation coefficient is17.99,and the theoretical calculated results are inconsistent with the experimental result.
基金Project supported by National Natural Science Foundation of China(21161013)Natural Science Foundation of Inner Mongolia(2011MS0202)+1 种基金the Opening Foundation for Significant Fundamental Research of Inner Mongolia(2010KF03)financial supported and from the Inner Mongolia University"211project"innovative training project
文摘Abstract： Ten solid terbium complexes with 2-pyrazinecarboxylic acid （Hpyca） and butanedioic acid （BDAH） were synthesized via coprecipitation method and characterized by elemental, EDTA titration, inductively coupled plasma （ICP）, thermogravim- etry-differential scanning calorimetry （TG-DSC） and infrared （IR） analyses. The results showed that the complexes had the composi- tions of Tb（pyca）（BDA）·2H2O, Tb0.5Y0.5（pyca）（BDA）·2H2O, Tb0.5La0.5（pyca）（BDA）·3H20, Tb0.5Gd0.5（pyca）（BDA）·2H2O, Tb0.7Y0.3（pyca）（BDA）·3HO, Tb0.7Lao.3（pyca）（BDA）-0.5H20, Tb0.TGd0.3（pyea）（BDA）＇H20, Tb0.6Y0.4（pyca）（BDA）·2.5H20, Tb0.6La0.4 （pyca）（BDA）·2.5H2O and Tbo.6Gd0.4（pyca）（BDA）·3H20. IR spectra indicated that the rare earth ions coordinated with the carboxylic oxygen atoms of Hpyca and BDAH. Luminescence spectra showed that the doped La3＋, y3＋ or Gd3＋ ions did not affect the lumines- cence emission peak positions, but remarkably increased the luminescent intensities of terbium complexes. Furthermore, the doped lanthanide complexes showed longer luminescence lifetimes and higher quantum yields than pure terbium complex. The enhanced luminescence efficiencies of Tb3＋ ions in the doped complexes might result from the antenna effect of the two carboxylate ligands as well as the decrease of the self-quench of the Tb3＋ ions induced by the doped lanthanide ions.
文摘The effect of an anionic surfactant (sodium dodecyl sulfate, SDS) on the fluorescence properties of nucleic acid with terbium (III) is studied. Results show that ribonucleic acid (RNA) presents fluorescence reaction with Tb (III) directly, but deoxyribonucleic acid (DNA) presents similar fluorescence reaction only after its denaturation. In the presence of SDS, the fluorescence intensity is 4.0 times and 3.5 times greater than that of DNA and RNA without SDS.
基金Project supported by the National Key Technologies R&D Program(2014BAC03B04)
文摘The effect of mechanical activation （MA） on the kinetics of terbium （Tb） leaching from waste phosphors using hydrochloric acid was investigated. Leaching kinetics, such as apparent reaction rate, activation energy and reaction order, were determined using the shrinking-core model and the Arrhenius equation. Results obtained from experiments with different concentrations of HC1 and under different leaching temperatures were used for the determinations. The impacts of factors such as rotational speed, HC1 concen- tration and leaching temperature on the leaching rate of Tb were also discussed. The results showed that MA could dramatically increase the leaching rate of Tb from waste phosphors, and the apparent reaction rate （kap） of leaching was accelerated as well. For inactivated waste phosphors, the apparent activation energy （Eap） was 52.82±3.95 kJ/mol, indicating that the rate-controlling step of the leaching process was the chemical reaction. The Eap dropped to 25.96 ±3.90 kJ/mol and 10.96±2.79 k J/tool when the waste phosphors were mechanically activated at rotational speeds of 400 and 600 r/min, respectively; the leaching process transformed to a hybrid （chemical-reaction and diffusion） control process, and even a reagent-diffusion （through the product layer） control process. The apparent reaction order for Tb leaching from 400 r/min-activated waste phosphors was 2.49±0.11, and it decreased to 1. 16±0.17 when the rotational speed of 600 r/min was used. Kinetics results indicated that MA could make Tb leaching occur spontaneously, and thc activation intensity of waste phosphors was strengthened with higher rotational speed.
基金The project is financially supported by the Natural Science Foundation of Hebei Province (No. 202140 and No. 203148)
文摘A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by X-ray diffraction. The crystal of the complexTb(o-MBA)_3phen belongs to triclinic crystal system and P1 (#2) space group. The crystal data are asfollows: a = 1.4371(4) nm, b = 1.7387(2) nm, c = 1.3109(2) nm, α = 96.37(1)°, β = 107.21(2)°,γ= 82.78(2)°, Ⅴ= 3.094(1) nm^3, Z= 2, M_r = 1489.12, D_c= 1.598 g·cm^(-3), μ = 2.330 mm^(-1)and F(000) = 1488.00. The final R and R_w are 0.038 and 0.047 for 8668 [Ⅰ > 2σ(Ⅰ)] uniquereflections, respectively. In the complex each Tb^(3+) ion is eight-coordinated by one1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups.The carboxylate groups are bonded to the terbium ion in two modes: the chelating bidentate and thebridging bidentate. Excitation and luminescence data observed at room temperature show that thetitle complex emits strong green fluorescence under ultraviolet light. The results of thermalanalysis indicate that the complex Tb(o-MBA)_3phen is quite stable to heat.
基金Project supported by National Natural Science Foundation of China(21003063)the Natural Science Foundation of Heilongjiang Province ofChina(B201006,B201015)+3 种基金Research Project of Heilongjiang Provincial Health Bureau of China(2012-263,2010-504)Chinese MedicineResearch Project of Heilongjiang Province(ZHY12-Z195)supported by the Scientific and Technical Research Project of Education Department of Heilongjiang Province(11551482)2012 Graduate Innovation Scientific Research Project Funds of Jiamusi University and Great Foster Projectof Jiamusi University(LZP2011-003)
文摘Fluorescence characteristics of complex system of rare earth terbium （Tb3＋）, norfloxacin, 1,10-phenanthroline（1,10-phen） and sur- factant sodium dodecyl benzene sulfonate （SDBS） had been studied by using fluorescence spectroscopy. In a buffer solution （pH=6.3）, the fluorescence intensity of the norfloxacin-Tb3＋ （NFLX-Tb3＋） system had been remarkably enhanced by SDBS and 1,10-Phen. When excited at 335 nm, a good linear relationship between fluorescence intensity of NFLX-Tb3＋ system and NFLX concentration was obtained in the range of 8× 10-8-4× 10-6 mol/L, and the linear equation was F=2× 10^8 CNFLX＋22.7 with correlation coefficient of 0.9959. In addition, this method was compared with some previous literatures, the proposed method had relatively higher sensitivity and lower detect limit. The method was sim- ple, rapid, sensitive, practical and suitable for direct analysis of pharmaceutical preparation. It was successfully applied to determine the cap- sules, human serum and urine in real pharmaceutical samples.
文摘The binding of Tb 3+ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb 3+ at 549 nm. The conditional equilibrium constants for the complexation of Tb 3+ by chicken apoovotransferrin in 0 1 mol/L hepes, at pH 7 4 and room temperature were measured. The successive macroscopic binding constants are lg K 1=9 08±0 12 and lg K 2=7 36±0 22. The molar fluorescence enhancement of Tb 3+ apoovotransferrin complex is (2 06±0 14)×10 4 mol -1 ·L. The fluorescence quenching experiment and the titration of N terminal monoferric ovotransferrin showed that Tb 3+ has a preference for being bound to the N terminal binding site of apoovotransferrin.
文摘The phenomenon of fluorescence enhancement for the system of terbium( Ⅲ ) with trimesic acid [ ben-zene-1, 3, 5-tricarboxylic acid (TMA)] in the presence of an excase of La￣(3+) in gelatin aqusous solution wasstudied. The fluorescence intensity of Tb￣Ⅲ -TMA system can be greatly increased by La￣(3+) , which causedthe largest enhancement of the fluorescence intensity over two orders of magnitude. The intermolecular transfer of energy was responsible for the mechanism of the fluorascence enhancement. Gelatin plays animportant role for the stabilization of the system. The system, having the maximum excitation and emis-sion wavelengths at 260 nm and 549 nm, respectively, shows a constant fluorescence interisity over the pHrange 4～6. The fluorescence intensity is a linear function of Tb￣(3+) concentration in the range of 8. 0 ×10 ￣(-9)～ 2. 6 × 10￣(-7) mol· L￣(-1) and the limit of detection is 2.0 × 10￣(-9) mol·L￣(-1) . The optimized procedurewas used for the determination of trace amount of terbium in rare earth oxides and international standardreference rocks with satisfactory results.
文摘Poly (N-vinylacetatnide) ( PNVA) was synthesized by free radical polymerization in ethanol solution, in which alpha, alpha'-azobisisobutyronitrile was used as an initiator. Tb(III)-PNVA polymer was prepared and characterized by ultraviolet-visual (UV), fourier transform infrared (FIF-IR), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. The experimental results of UV, FT-IR and XPS show that the Tb (III)-PNVA electrovalent complex is formed by electrostatic interaction between terbium (III) cation and complexible atoms of acylamino group in the pendant chain of the polymer. The fluorescence spectrum of the complex exhibits intensive characteristic emission of terbium at 490, 545 and 584 run, which are assigned to D-5(4)->F-7(6), D-5(6)->F-5(6) and D-5(4)->F-7(3) transition, indicating that there exists an efficient intermolecular energy transfer from the polymer ligand to the central rare earth ion. The emission intensity of the complex is increased with the increasing concentration of Tb (III) ion until the weight ratio of Tb (III) on to PNVA is 1.5% (mass fraction), and decreased with the further increasing concentration of Tb (III) ion, which is a typical concentration quenching behavior.
基金supported by the National Natural Science Foundation of China (Nos. 21572091 and 21472075)the Fundamental Research Funds for the Central Universities (No. lzujbky-2016-51) by Ministry of Education of China
文摘By modifying the salicylic-acid moiety with electron-withdrawing or –donating groups, three new terbium complexes（LⅠ·Tb, LⅡ·Tb, L·（Ⅲ）Tb） based on tripodal carboxylate ligands were synthesized. Due to different pull-push electronic effects of ligands, the fluorescence intensities of these terbium complexes significantly varied, that is： LⅡ·Tb 〉L（Ⅲ）·Tb〉 LⅠ·Tb. Meanwhile, the characteristic peaks at 492 nm（5D4→7F6） and 547 nm（5 D4→7F5） showed ＂Off–On–Off＂ fluorescence response to various p H conditions,which indicated that all of them can be used as the highly sensitive pH fluorescent probes. Notably, using LⅡ·Tb with the best fluorescence performance as a probe, some patients＇ urine samples can be easily monitored through the response triggered by pH value. Therefore, LⅡ·Tb has the potential to auxiliarily diagnose some diseases in clinical practice through p H detection of routine urine test.
基金Supported by the NSF of China(21361013,31460488)NSF of Fujian(2018J01447)+1 种基金Jiangxi Provincial Department of Education’s Item of Science and Technology(GJJ170637)the Open Foundation(20180008)of State Key Laboratory of Structural Chemistry
文摘A novel terbium-mercury complex [Tb(IA)3(H3 O)2]2 n(2 n HgCl4)(n Hg2 Cl5)·n H3 O· 3 n H2 O(1, HIA = isonicotinic acid) has been synthesized through hydrothermal reactions and characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in the C2/c space group of monoclinic system with a = 24.2347(5), b = 20.8342(6), c = 15.3206(3) ?, β = 128.257(2)°, V = 6074.3(2) ?3, C36H41Cl13Hg4N6O20Tb2, Mr = 2458.80, Z = 4, Dc = 2.689 g/cm3, μ(Mo Kα) = 13.014 mm–1 and F(000) = 4520. The crystal structure of 1 is characterized by a one-dimensional(1-D) chain-like structure. Solid-state UV/Vis diffuse reflectance spectrum reveals the existence of a wide optical band gap of 3.36 eV. Solid-state photoluminescence experiment uncovers that it shows reddish brown upconversion emission. The emission bands are originated from the characteristic emission of the 4 f electrons intrashell transition of the 5D4 → 7 FJ(J = 6, 5, 4) of the Tb3+ ions. Energy transfer mechanism is explained by the energy level diagram of the Tb3+ ion and the isonicotinic acid ligand. It shows a remarkable CIE chromaticity coordinates(0.4158, 0.4005).
基金financial supports from the National Natural Science Foundation of China (Nos.81760601, 21265013 and 81260435)the Natural Science Foundation of Jiangxi Province(No.20171BAB215050)the Innovation Fund Designated for Graduate Students of Jiangxi Province(No.YC2017S085)
文摘We report a facile, effective and rapid screening method for the determination of total fluoroquinolones(FQs) in milk using lanthanide coordination polymer nanomaterials as the sensing platform. The nonluminescent coordination polymer nanosheets(CPNSs) used in this work are composed of adenosine monophosphate(AMP) and terbium(Tb^(3+)) ions(AMP/Tb CPNSs). The as-prepared CPNSs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and fluorescence techniques. Tb^(3+) acts as the center ion of the coordination polymer, with AMP assembled through phosphate and amine groups. However, the reaction between FQs and AMP/Tb CPNSs noticeably turns on the fluorescence due to the strong coordination interaction between FQs and Tb^(3+). Under optimized conditions, the fluorescence intensity of AMP/Tb at 545 nm shows a linear relationship with FQ concentrations between 0.04 μmol/L and 5.0 μmol/L. The relative standard deviation(RSD) of the intraday precision is below 1%, and detection limits are as low as 0.01 μmol/L. The proposed method was successfully applied to the determination of FQs in milk samples.
