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1.
Jun-Gill Kang Tack-Jin Kim Hee-Jung Kang Younbong Park Min-Koo Nah 《Journal of luminescence》2008,128(12):1867-1872
Two novel complexes of Sm(III) and Dy(III) with mixed oxydiacetate (ODA) and 1,10-phenanthroline (phen) ligands were synthesized and their structure and luminescence properties were characterized. The complexes of [Ln(ODA)(phen)·4H2O]Cl·5H2O [Ln=Sm and Dy] crystallize in the monoclinic space group P21/n with Sm: a=12.3401(14) Å, b=16.821(2), c=12.6847(11) Å, β=107.939(10)°, V=2505.0(5) Å3, Z=4 and ρ=1.841 mg/m3, and with Dy: a=12.289(7) Å, b=16.805(6) Å, c=12.705(4) Å, β=108.144(18)°, V=2493.4(19) Å3, Z=4 and ρ=1.786 mg/m3. The complexes of [Sm(ODA)(phen)·4H2O]+ and [Dy(ODA)(phen)·4H2O]+ excited by UV light produce orange red and lightly white emissions, respectively, via the nonradiative energy transfer from phen to the metals. The quantum yield of the sensitized luminescence of [Dy(ODA)(phen)·4H2O]+ (Q=19%) is much greater than that of [Sm(ODA)(phen)·4H2O]+ (Q=1.4%). The luminescence decay times of the complexes were in a few microsecond range and independent of temperature. 相似文献
2.
Rare-earth complexes [(TbxTmy)L5(ClO4)2](ClO4)·3H2O(x:y=1.000:0.000, 0.999:0.001, 0.995:0.005, 0.990:0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200, 0.700:0.300; L=C6H5COCH2SOCH2COC6H5) were synthesized and characterized with elemental analysis, infrared spectra (IR) and 1H NMR. The photophysical properties of these complexes were studied in detail with ultraviolet absorption spectra, fluorescent spectra and lifetimes. The fluorescence spectra and decay curves of complexes indicated that the fluorescence emission intensity was enhanced and the fluorescence lifetime was prolonged by Tm (III), which may be due to the intra-molecular energy transfer between inert rare-earth ions and active rare-earth ions. The complexes showed the best properties when the mole ratio of Tb (III) to Tm (III) is 0.995:0.005. The intensity of fluorescence can be increased to 208%. Additionally, the energy-transfer mechanisms between the ligand and the central Tb (III) ions were discussed. 相似文献
3.
Cuikun Lin 《Journal of luminescence》2010,130(10):1907-1915
The effects of colloidal-gold layers on the luminescent properties of thin films of Eu(TTFA)3(TTFA=thenoyltrifluoroacetonate) in PMMA (PMMA=poly(methyl methacrylate)) were investigated. Layers of spherical gold nanoparticles (12 nm) were formed by self-assembly on the surface of amino-derivatized glass slides. Eu(TTFA)3-PMMA films were then spin-coated either directly onto the Au metal surfaces or onto spacer layers covering the gold. The luminescence properties were characterized both as a function of the density of Au particles in the colloidal layer, and as a function of the distance between the Au layer and the luminescent film. The distance between the metal and luminescent layers was controlled using polyelectrolyte spacer layers deposited on the colloidal-gold films by a spin-assisted, layer-by-layer (SA-LBL) method. It was found that the colloidal gold layer has a net quenching effect on Eu(TTFA)3 luminescence under all conditions considered in this study. The luminescence intensities and lifetimes decrease with increasing density of Au nanoparticles and with decreasing separation (d) between the luminescent film and the gold layer. The measured luminescence intensity drops more quickly with decreasing distance than one would predict based solely on lifetime data, if one assumes a constant radiative relaxation rate. Fits of the luminescence decay kinetics to a model for non-radiative energy-transfer from Eu(TTFA)3 to the gold layer yields a 1/d2 dependence, where d is the distance from the gold layer to the nearest face of the luminescent film. It is suggested that there is no reasonable physical interpretation of this result within the constraints of the model and, therefore, the interaction between the luminescent and gold layer cannot be explained solely in terms of non-radiative energy transfer. 相似文献
4.
基于邻菲咯啉的反应型三元铕配合物的合成与荧光性质 总被引:1,自引:0,他引:1
以二苯甲酰甲烷(HDBM)为第一配体,5-丙烯酰胺基-1,10-菲咯啉(Aphen)为活性第二配体,制备了新的反应型三元铕配合物Eu(DBM)3Aphen。通过元素分析、红外光谱和热分析对配合物进行了组成确定,采用紫外光谱、荧光光谱、荧光寿命和荧光量子产量研究了配合物的光物理性能。结果表明,在紫外光激发下,配合物Eu(DBM)3Aphen能发射Eu3+的特征荧光,其荧光发射强度、单色性、荧光寿命和荧光量子产率等均显著高于文献报道的丙烯酸配合物Eu(DBM)2AA的相应数值,表明配合物Eu(DBM)3Aphen不仅可作为潜在的红色发光材料,还可作为反应型的配合物,为制备具有优异发光性能的稀土聚合物提供了一条新的途径。 相似文献
5.
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu2O3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt. 相似文献
6.
Microwave-assisted synthesis method enabled the preparation of the (tris-acetylacetonate)(2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolinate) terbium(III) (Tb(acac)3(dmdpphen)) complex with outstanding high green luminescence. This method is appropriate for green chemistry and energy-saving processes. The Tb(acac)3(dmdpphen) complex has good thermal stability. Emission peaks are assigned to the f-f transitions of the Tb3+. The Tb(acac)3(dmdpphen) complex is expected to be used in functional materials of electronic products. 相似文献
7.
Philip Lenaerts 《Journal of luminescence》2006,117(2):163-169
Sol-gel glasses with covalently linked lanthanide complexes are luminescent materials which can be processed at ambient temperatures, which have a good solubility and uniform distribution of the complexes in the host matrix. In this study, a luminescent terbium(III) complex was covalently coupled to an organic-inorganic hybrid material prepared by the sol-gel process. This was realised by use of nicotinate groups as the ligands for the terbium(III) ion. The [Tb(C5H4NCO2)3(phen)(H2O)2] complex was immobilised on the sol-gel glass matrix and showed a green photoluminescence upon irradiation with ultraviolet light. The nicotinate groups act as an antenna to absorb the incident light and channel the excitation energy to the terbium(III) ion. The sol-gel glass was also prepared for the corresponding europium(III) complex. In this case, excitation of the europium(III) ion was possible via both the nicotinate ligands and the 1,10-phenanthroline ligands. High-resolution luminescence and excitation spectra were recorded and the radiative lifetimes were measured. 相似文献
8.
The spectral and kinetic parameters of LiCaAlF6:Pr and LiSrAlF6:Pr single crystals are studied at LHeT and room temperature (RT). Photon cascade emission (PCE), i.e., 1S0→1I6 and 3P0→3Hj, 3Fj transitions after Pr3+ excitation via 4f2→4f 5d absorption results in the conversion of the vacuum ultraviolet photon to two visible photons. The excitation and photoemission spectra as well as decay times have been measured and compared with those for CaF2:Pr and SrF2:Pr crystals. X-ray luminescence was measured to study the emission origin from both 1S0 and 3P0 states of Pr3+. An intense phosphorescence of LiSrAlF6:Pr was observed in the visible range after X-irradiation at RT, contrary to LiCaAlF6:Pr. 相似文献
9.
Two novel ternary rare earth complexes LnL5L′(ClO4)32H2O (Ln=Eu(III), Tb(III); L=bis(benzoylmethyl) sulfoxide, L′=phen) were synthesized and characterized by elemental analysis, coordination titration analysis, molar conductivity, IR, TG-DSC,1H NMR and UV spectra. The fluorescence spectra illustrated that both the Eu(III) and Tb(III) ternary complexes displayed strong characteristic metal-centered fluorescence in solid state. After the introduction of the second ligand phen group, the relative emission intensities and fluorescence lifetimes of the ternary complex EuL5L′(ClO4)32H2O (L=C6H5COCH2SOCH2COC6H5, L′=phen) enhanced more obviously than that of the binary complex EuL5(ClO4)33H2O. This indicated that the presence of both organic ligands bis(benzoylmethyl) sulfoxide and the second ligand phen could sensitize fluorescence intensities of Eu(III) ions, and the introduction of phen group was resulted in the enhancement of the fluorescence properties of the Eu(III) ternary rare earth complexes. The phosphorescence spectra are also discussed. 相似文献
10.
The previously reported1 linear correlation between the extinction coefficient of the longest wavelength band and the sum of the Hammett op+ values in arenetricarbonylchromium complexes has been extended to now include fifty-seven compounds. A possible “meta effect” and the solvent sensensitivity of these compounds was also studied. 相似文献
11.
A series of rare earth (Gd, Eu, Tb) complexes with different substituent group carboxylic acids (ortho-hydroxylbenzioc acid, ortho-aminobenzoic acid and ortho- methoxy benzoic acid) and 1,10-phenanthroline were synthesized. The spectroscopic studies of the photophysical properties such as luminescence properties, energy match and intramolecular energy transfer were carried out. The lowest triplet state energies of ligands and the intramolecular energy transfer efficiencies were determined with the measurement of low phosphorescence spectra and lifetimes of Gd complexes. 相似文献
12.
N. Shanta Singh R.S. Ningthoujam S. Dorendrajit Singh B. Viswanadh N. Manoj R.K. Vatsa 《Journal of luminescence》2010,130(12):2452-2459
Highly crystalline spherical nanoparticles of MVO4:Tm3+ (M=Gd, Y) having a size of 20–45 nm were prepared using ethylene glycol as both capping agent and reaction medium. X-ray diffraction study shows linear decrease in the unit cell volume with an increase in Tm3+ concentrations in MVO4 (M=Gd, Y; Tm3+=0, 2, 5, 7, 10, 15, 20, 40, 60, 80 and 100 at%), indicative of quantitative substitution of Gd3+/Y3+ lattice sites by Tm3+ ions in MVO4. Blue light emission at 475 nm is observed after excitation at 310 nm due to energy transfer from VO43− absorption band to Tm3+. Emission intensity and average decay lifetime increase with an increase in heat treatment from 500 to 900 °C. This has been attributed to an extent of reduction in non-radiative process arising from surface. The emission intensity of Tm3+ in GdVO4 host is higher than that in YVO4 and thus the former host is better. Quantum yield increases with increase in heat-treatment temperature. This material will be the alternative blue light emitter. 相似文献
13.
X.H. Zhao K.L. Huang F.P. Jiao Z.G. Liu 《Journal of Physics and Chemistry of Solids》2007,68(9):1674-1680
This work reports the synthesis and luminescent properties of complexes of europium(III) with 2-thienyltrifluoroacetonate (HTTA), terephthalic acid (TPA) and phenanthroline (Phen), in the solid state. The new complexes were characterized by elemental analysis, infrared (IR) spectroscopy, scanning electronic microscopy (SEM) and thermal stability analysis. Both binuclear complex Eu2(TPA)(TTA)4Phen2 and polynuclear complex Eu(TPA)(TTA)Phen present better thermal stability than the mononuclear complex Eu(TTA)3Phen does. The formation of the binuclear/polynuclear structure of the complexes appears to be responsible for the enhancement of the thermal stability. The emission spectra show narrow emission bands that arise from the 5D0→7FJ (J=0-4) transition of the Eu3+ ion. The spectral data of the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 present only one sharp peak in the region of the 5D0→7F0 transition indicating that only one Eu3+ ion species is present in each sample. In addition, the luminescence decay curves of the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 fit a single-exponential decay law. The values of quantum efficiencies of the emitting 5D0 level for the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 are 29% and 28%, respectively. 相似文献
14.
A novel co-luminescence system based on the formation of a complex between europium (III) (Eu3+) and gatifloxacin (GFLX) in sodium dodecylbenzene sulfonate (SDBS) micelle solution containing lanthanum (III) (La3+) has been developed for the determination of Eu3+. The experimental results show that the complex formed by Eu3+ and GFLX here can emit the characteristic luminescence of Eu3+. With the addition of La3+, the luminescence intensity of the system was enhanced about 7-fold compared with that without La3+. Under the optimal conditions, the luminescence intensity exhibits an excellent linear relationship with Eu3+ concentration in the range of 1.0×10−10-5.0×10−8 mol L−1. The correlation coefficient (r) is 0.9998, and the detection limit (3σ) is 7.0×10−14 mol L−1. A test method with satisfactory accuracy based on this system was applied to determine trace amounts of Eu3+ in rare earth samples. In addition, the detailed luminescence mechanism of this system was investigated by analyzing the ultraviolet absorption spectra, surface tension, fluorescence polarization, quantum yield, and the number of water molecules in the first coordination sphere of the Eu3+ complex. 相似文献
15.
We have studied the spectral luminescence properties of mixed-ligand complexes of Eu(III) ions with tetracyclines and hydrogen
peroxide. We have established that incorporation of hydrogen peroxide into the inner sphere of these complexes leads to a
significant increase (by a factor of 10–25) in the intensity of luminescence of the Eu(III) ions, redistribution of the intensities
of the 5D0 → 7Fj transitions, in particular to an anomalous increase in the intensity of the band for the forbidden transition 5D0 → 7F0.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 310–314, May–June, 2007. 相似文献
16.
Three types of europium complexes were synthesized by introducing benzoylacetone as the first ligand and 1, 10-phenanthroline, triphenylphosphine oxide, 2,2'-bipyridyl as the second ligand, respectively. The properties of above materials were characterized by infrared absorption spectra, UV-Vis absorption spectra and fluorescence spectra. Then, it was discussed that the different second ligands of europium complexes can affect their luminescence properties, and their intramolecular energy transfer models had been set up. The results indicated that ligands and complexes have a strong absorption of UV light and the three types of europium complexes exhibit characteristic luminescence of europium ion when excited by UV light. In addition, it is suggested that the fluorescence yield of europium complexes mostly depend on both the energy difference between the second ligand and the Eu3+ ion and the energy difference between the second ligand and the first ligand. 相似文献
17.
Six new ternary rare-earth (La, Eu, Sm, Nd, Y, Yb) complexes with L-isoleucine and 1,10-phenanthroline have been synthesized. Their compositions were characterized as RE(Ile)3PhenCl3 · 4H2O (RE = La, Eu, Sm, Nd, Y, Yb; Ile = L-isoleucine; phen = 1,10-phenanthroline) by elemental analysis, EDTA titration, molar conductance measurement, UV spectra, FT-IR spectra, and TG-DTA. The average diameters of growth inhibition area and the minimal inhibitory concentration (MIC) of the complexes were studied by disc diffusion method and dilution method in nutrient broth. The results showed that the ternary rare-earth complexes strongly exhibited the antibacterial activity against Escherichia coli and Staphylococcus aureus and that their antibacterial effects were better than those of rare-earth chlorides, L-isoleucine, and 1,10-phenanthroline. 相似文献
18.
Enhai Song Weiren Zhao Wei Zhang Huachu Ming Yuchun Yi Mingkang Zhou 《Journal of luminescence》2010,130(12):2495-2499
Eu2+ and Mn2+ co-doped Ba2Ca(BO3)2 phosphors yield two emission bands consisting of green and red components under the excitation of 360 nm, which shows a great potential for white LEDs. Effective energy transfer occurs in Eu2+/Mn2+ co-doped Ba2Ca(BO3)2 host due to the large spectral overlap between the emission of Eu2+ and the excitation of Mn2+. The energy transfer from Eu2+ to Mn2+ is thoroughly investigated by their excitation, emission and photoluminescence decay behaviors, and is demonstrated to be via the dipole–quadrupole interaction. 相似文献
19.
A novel method of luminescence enhancement effect for the determination of balofloxacin (BLFX) was proposed. A new system of the BLFX-Eu3+-SDBS (sodium dodecylbenzene sulfonate) was investigated. It was found that SDBS significantly enhanced the luminescence intensity of the BLFX-Eu3+ complex (about 20-fold). Under the optimized experimental conditions, the system exhibits an excellent linear relationship between the enhanced luminescence intensity and the concentration of BLFX over the range of 1.0×10−8-8.0×10−7 mol L−1 with a correlation coefficient (R) of 0.9994, and the detection limit (3σ) of the method was determined as 2.0×10−9 mol L−1. This method has been successfully applied for the determination of BLFX in pharmaceuticals and human urine/serum samples. Compared with most of the other methods reported, the rapid and simple procedure proposed in the text offers higher sensitivity, wider linear range, and better stability. 相似文献
20.
YVO4:Eu3+-based red-emitting phosphors with the compositions of Y0.95−xVO4:0.05Eu3+,xBi3+ (x=0.01, 0.03, 0.05, 0.07 and 0.09) and Y0.90(V1−zPz)O4:0.05Eu3+,0.05Bi3+ (z=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized by the high temperature solid-state method. The as-prepared phosphors have the similar tetragonal phase structure and their morphologies varied with the relative content ratio of V to P. The photoluminescence spectra for the as-synthesized phosphors show that a dominant red emission line at around 619 nm, which is due to the Eu3+ electric dipole transition of 5D0-7F2, is observed under different excitation wavelengths (254 and 365 nm). Further, the emission intensities of 5D0-7F2 transition upon 365 nm excitation increase sharply owing to the Bi3+ doping. Energy transfer process, luminescent lifetime and quantum efficiency for the selected Y0.90(V1−yPy)O4:0.05Eu3+,xBi3+phosphors were also studied in detail. 相似文献