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1.
Enhancement of Europium Luminescence in Tetracycline–Europium Complexes in the Presence of Urea Hydrogen Peroxide 总被引:2,自引:2,他引:0
An increase in the europium emission band was observed, for the first time, with addition of urea hydrogen peroxide to the
tetracycline–europium (Tc–Eu)solution. We have observed that the wavelength, the band width and the area of 5D0→7F2 europium transition change with the urea hydrogen peroxide concentration. We claim that the tetracycline–europium complexes
can be used as probes of urea hydrogen peroxide concentration. 相似文献
2.
Chemiluminescence (CL) of the reaction system tetracycline–H2O2–Fe(II)/(III)–Eu(III) was used for the determination of tetracycline hydrochloride in water, pharmaceutical preparations,
and honey. The CL spectrum registered for this system shows emission bands typical of Eu(III) ions, with a maximum at λ ∼ 600 nm,
corresponding to the electronic transitions of 5D0 → 7F1 and 5D0 → 7F2. A strong chemiluminescence intensity characteristic of europium(III) ions in the system tetracycline–H2O2–Fe(II)/(III)–Eu(III), as contrasted to the emission of the system tetracycline–H2O2–Fe(II)/(III) without Eu(III), proves that the Eu(III) ion plays the role of a chemiluminescence sensitizer, accompanying
tetracycline oxidation in the Fenton system (H2O2–Fe(II)/(III)). A linear dependence was observed for the integrated CL light intensity on the tetracycline concentration in
the range of 2 × 10−7 to 3 × 10−5 mol l−1 with the detection limit of 5 × 10−8 mol l−1 in aqueous solution. 相似文献
3.
I. R. Mardaleishvili P. P. Levin V. B. Ivanov 《Russian Journal of Physical Chemistry B, Focus on Physics》2009,3(4):560-566
The kinetics of luminescence and transformation of short-lived products of the photolysis of europium and lanthanum complexes
with thenoyltrifluoroacetone and 1,10-phenanthroline and their mixtures in polymethyl methacrylate films was studied by the
nanosecond laser photolysis method with recording both light emission and absorption. Fast (535 and 585 nm, 5
D
1 → 7
F
0, 7
F
3, decay time 0.7 μs) and slow (613 nm, 5
D
0 → 7
F
2, luminescence rise and decay times 0.7 μs and 0.5 ms, respectively) luminescence was studied. Induced absorption with a maximum
at 600 nm and decay time ∼3 ms was observed; this absorption was assigned to triplet states of the deprotonated form of thenoyltrifluoroacetone.
The dependences of luminescence intensity on the concentration of the components in a mixture of complexes were analyzed,
and synergistic effects of luminescence strengthening were estimated. The kinetics of a decrease in luminescence intensity
during photolysis was studied. Possible mechanisms of a decrease in the relative initial process rate and an increase in the
quasi-stationary value of relative luminescence intensity as the concentration of complexes in the polymer increased were
discussed. 相似文献
4.
We have found that it is possible to enhance the luminescence of Pr(III) in solutions of complexes with β-diketones: acetylacetone
derivatives containing fluoroalkyl substituents of different lengths and structures. We have established that in the presence
of organic solvents, second (additional) ligands, and surfactants shielding the central ion from the quenching effect of the
water molecules (OH oscillators), the intensity of luminescence for Pr(III) increases by a factor of 65, 38, and 45 respectively.
In this case, cationic surfactants form ionic associates with Pr(III) β-diketonates, with incorporation of one more β-diketone
molecule (ratio Pr:β-diketonate:surfactant = 1:4:1). As a result of suppression of intramolecular energy losses in solutions
of Pr(III) β-diketonates, it is possible to observe its rather intense luminescence at 605 nm (the transition 1D2 → 3H4), 612 nm (3P0 → 3H6), and 646 nm (3P0 → 3F2).
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 746–750, November–December, 2006. 相似文献
5.
In this paper, Eu3+ β-diketone Complexes with the two ligands 1-(2-naphthoyl)-3, 3, 3-trifluoroacetonate (TFNB) and 2’2-bipyridine (bpy) have
been synthesized. Furthermore, we reported a systematical study of the co-fluorescence effect of Eu(TFNB)3bpy doped with inert rare earth ions (La3+, Gd3+ and Y3+) and luminescence ion Tb3+. The co-luminescence effect can be found by studying the luminescence spectra of the doped complexes, which means that the
existence of the other rare earth ions (La3+, Y3+, Gd3+ and Tb3+) can enhance the luminescence intensity of the central Eu3+, which may be due to the intramolecular energy transfer between rare earth ions and Eu3+. The efficient intramolecular energy transfer in all the complexes mainly occurs between the ligand TFNB and the central
Eu3+. Full characterization and detail studies of luminescence properties of all these synthesized materials were investigated
in relation to co-fluorescence effect between the central Eu3+ and other inert ions. Further investigation into the luminescence properties of all the complexes show that the characteristic
luminescence of the corresponding Eu3+ through the intramolecular energy transfers from the ligand to the central Eu3+. Meantime, the differences in luminescence intensity of the 5D0→7F2 transition, in the 5D0 lifetimes and in the 5D0 luminescence quantum efficiency among all the synthesized materials confirm that the doped complex Eu0.5Tb0.5(TFNB)3bpy exhibits higher 5D0 luminescence quantum efficiency and longer lifetime than the pure Eu(TFNB)3bpy complex and other materials. 相似文献
6.
I. N. Ogorodnikov N. E. Poryvay I. N. Sedunova A. V. Tolmachev R. P. Yavetskiy 《Physics of the Solid State》2011,53(2):263-270
The thermally stimulated recombination processes and luminescence in crystals of the lithium borate family Li6(Y,Gd,Eu)(BO3)3 have been investigated. The steady-state luminescence spectra under X-ray excitation (X-ray luminescence spectra), the temperature
dependences of the X-ray luminescence intensity, and the glow curves for the Li6Gd(BO3)3, Li6Eu(BO3)3, Li6Y0.5Gd0.5(BO3)3: Eu, and Li6Gd(BO3)3: Eu compounds have been measured in the temperature range 90–500 K. In the X-ray luminescence spectra, the band at 312 nm
corresponding to the 6
P
J
→ 8
S
7/2 transitions in the Gd3+ ion and the group of lines at 580–700 nm due to the 5
D
0 → 7
F
J
transitions (J = 0–4) in the Eu3+ ion are dominant. For undoped crystals, the X-ray luminescence intensity of these bands increases by a factor of 15 with
a change in the temperature from 100 to 400 K. The possible mechanisms providing the observed temperature dependence of the
intensity and their relation to the specific features of energy transfer of electronic excitations in these crystals have
been discussed. It has been revealed that the glow curves for all the crystals under investigation exhibit the main complex
peak with the maximum at a temperature of 110–160 K and a number of weaker peaks with the composition and structure dependent
on the crystal type. The nature of shallow trapping centers responsible for the thermally stimulated luminescence in the range
below room temperature and their relation to defects in the lithium cation sublattice have been analyzed. 相似文献
7.
A. Lushchik Ch. Lushchik I. Kudryavtseva A. Maaroos F. Savikhin E. Shablonin E. Vasil’chenko 《Optics and Spectroscopy》2011,111(3):434-440
The processes of photon multiplication in insulators have been considered. The luminescence of Tb3+ ions (5
D
3 → 7
F
J
, 5
D
4 → 7
F
J
transitions) upon intracenter excitation, the optical excitation of oxyanions, or the formation of separated electrons and
holes has been studied for CaSO4 doped with Tb3+ and Na+ ions at 6–9 K. An increase in Tb3+ concentration from 0.2 to 4 at % and transition from single Tb3+-Na+ states to centers that contain two or three terbium ions leads to the redistribution of the luminescence intensities in favor
of the 5
D
4 → 7
F
J
transitions and increase in their efficiency due to the possibility of the cooperative 5
D
3 → 5
D
4 and 7
F
6 → 7
F
J
transitions and the 4f
75d
1 → 5
D
3 and 7
F
6 → 5
D
4 transitions in the two- and three-terbium centers. Based on the example of MgO single crystals with highly mobile excitons,
holes, and electrons, the migration of free excitons and holes toward Cr3+ ions in the crystal bulk and their exit from the bulk to the surface have been revealed at 9 K. Surface losses limit the
luminescence quantum yield of MgO:Cr3+, CaSO4:Tb3+, and many other materials. 相似文献
8.
The effect of temperature on the luminescence intensity of the two bands due to 5
D
1→7
F
1 and 5
D
0→7
F
1 transitions in Eu3+ on excitation with the 476.5 nm line from an Ar+ laser has been studied in tellurite and calibo glasses. It is interesting to note that the peak intensity of the 5
D
1→7
F
1 transition increases with increasing temperature where as that of the 5
D
0→7
F
1 transition decreases. The ratio of the intensities of the two bands have been used to estimate the temperature.
PACS 42.70 Ce 相似文献
9.
I. N. Ogorodnikov N. E. Poryvai I. N. Sedunova A. V. Tolmachev R. P. Yavetskii 《Optics and Spectroscopy》2011,111(3):441-450
The luminescence and recombination processes in crystals of lithium borates Li6Gd
x
Y1 − x
(BO3)3:Eu have been investigated. The steady-state X-ray luminescence (XRL) spectra, the temperature dependences of the XRL intensity,
and the thermally stimulated luminescence (TSL) spectra have been measured for the Li6Gd(BO3)3, Li6Eu(BO3)3, Li6Y0.5Gd0.5(BO3)3:Eu, and Li6Gd(BO3)3:Eu compounds in the temperature range of 90–500 K. It is established that the band at 312 nm, which is due to the 6
P
J
→ 8
S
7/2 transitions in Gd3+ ions and the group of lines at 580–700 nm, which are due to the 5
D
0 → 7
F
J
(J = 0 … 4) transitions in Eu3+ ions dominate in the XRL spectra. The XRL intensity in these bands increases several times with a change in temperature from
100 to 400 K for undoped crystals. The likely mechanisms of the observed temperature dependence of the XRL intensity and their
relationship with the features of electronic-excitation energy transfer in these crystals are discussed. The spectra of all
crystals under study exhibit a dominant composite TSL peak with a maximum at 110–160 K and a series of weaker peaks, the composition
and structure of which depend on the crystal type. The nature of the shallow traps, which are responsible for the TSL at temperatures
below room, and their relationship with the defects of lithium cation sublattice are discussed. 相似文献
10.
XiaoBo Chen ZengFu Song JinGuang Wu N. Sawanoboi M. Ohtsuka YongLiang Li Jing Zhou Ce Wang JinYing Liu Qiang Tian Ping Sun HongMei Jing 《中国科学G辑(英文版)》2008,51(12):1868-1876
The ultraviolet upconversion luminescence of Tm3+ ions sensitized by Yb3+ ions in oxyfluoride nanophase vitroceramics when excited by a 975 nm diode laser was studied. An ultraviolet upconversion
luminescence line positioned at 363.6 nm was found. It was attributed to the fluorescence transition of 1D2→3H6 of Tm3+ ion. Several visible upconversion luminescence lines at 450.7 nm, (477.0 nm, 462.5 nm), 648.5 nm, (680.5 nm, 699.5 nm) and
(777.2 nm, 800.7 nm) were also found, which result respectively from the fluorescence transitions of 1D2→3F4, 1G4→3H6, 1G4→3F4, 3F3→3H6 and 3H4→3H6 of Tm3+ ion. The careful measurement and analysis of the variation of upconversion luminescence intensity F as a function of the 975 nm pumping laser power P prove that the upconversion luminescence of 1D2 state is partly a five-photon upconversion luminescence, and the upconversion luminescence of 1G4 state and 3H4 state are respectively the three-photon and two-photon upconversion luminescence. The theoretical analysis suggested that
the upconversion mechanism of the 363.6 nm 1D2→3H6 upconversion luminescence is partly the cross energy transfer of {3H4(Tm3+), 3F4(Tm3+), 1G4(Tm3+)→1D2(Tm3+)} and {1G4(Tm3+)→3F4(Tm3+), 3H4(Tm3+)→1D2(Tm3+)} between Tm3+ ions. In addition, the upconversion luminescence of 1G4 and 3H4 state results respectively from the sequential energy transfer {2F5/2(Yb3+)→2F7/2(Yb3+), 3H4(Tm3+)→1G4(Tm3+)} and {2F5/2(Yb3+) →2F7/2(Yb3+), 3F4(Tm3+)→3F2(Tm3+)} from Yb3+ ions to Tm3+ ions.
Supported by the National Natural Science Foundation of China (Grant No. 10674019) 相似文献
11.
Wen-Xian Li Yu-Shan Zheng Xiao-Jun Sun Xiao-Yan Shi Wen-Juan Chai Tie Ren 《Journal of fluorescence》2010,20(1):235-241
A ligand with double sulfinyl groups, naphthyl-naphthalinesulphonylpropyl sulfoxide(dinaphthyl disulfoxide, L), was synthesized
by a new method and its several lanthanide (III) complexes were synthesized and characterized by element analysis, molar conductivity,
coordination titration analysis, IR, TG-DTA, 1HNMR and UV spectra. The composition of these complexes, were RE2(ClO4)6·(L)5·nH2O (RE = La, Nd, Eu, Tb, Yb, n = 2 ∼ 6, L = C10H7SOC3H6SOC10H7). The fluorescent spectra illustrated that the Eu (III) complex had an excellent luminescence. It was supposed that the ligand
was benefited for transferring the energy from ligand to the excitation state energy level (5D0) of Eu (III). The Tb (III) complex displayed weak luminescence, which attributed to low energy transferring efficiency between
the average triplet state energy level of ligand and the excited state (5D4) of Tb (III). So the Eu (III) complex displayed a good antenna effect for luminescence. The phosphorescence spectra and the
relationship between fluorescence lifetime and fluorescence intensity were also discussed. 相似文献
12.
Oxyfluoroborate glass co-doped with Eu and Yb ions has been prepared and characterized for its optical properties through
photoluminescence, absorption and lifetime measurements. An intense red upconversion is observed from the 5D0 level of Eu3+ ions through energy transfer from Yb3+ to Eu3+ ion when excited with 980 nm. The Judd–Ofelt parameters have been evaluated to estimate the local site symmetry around the
Eu3+ ions. These parameters have been used to derive radiative properties such as transition probabilities, branching ratios,
radiative lifetimes and stimulated emission cross-sections for the 5D0–7FJ transitions. Decay of excitation of the 5D0 level has been measured by monitoring the 5D0→7F2 transition (613 nm) at room temperature. Quantum efficiency for this transition is found to be 73%. We also monitored the
effect of temperature on the fluorescence emission of Eu3+.
PACS 42.70.Ce; 42.70.Hj 相似文献
13.
A decrease in the wavelength of the 5
D
0→7
F
0 luminescence line of a Eu3+ ion in a single crystal of the superionic conductor Na5Y(:Eu)Si4O12 is observed as a consequence of raising the temperature. The effect is interpreted as the result of a change in the distribution
of mobile Na+ cations in the second coordination sphere of the luminescing rare-earth ion.
Fiz. Tverd. Tela (St. Petersburg) 39, 1997–2000 (November 1997) 相似文献
14.
E. B. Sveshnikova V. E. Lanin E. V. Krutineva V. L. Ermolaev 《Optics and Spectroscopy》2000,89(3):360-368
We studied sensitization of Eu(III) and Tb(III) ions by molecules of 1,10-phenanthroline and 2,2-bipyridil in D2O and d 6-ethanol and the influence of Nd(III), Pr(III), Sm(III), Gd(III), and Ho(III) ions on the luminescence intensity I lum and lifetime τlum of Eu(III) and Tb(III) in solutions. The stability constants of complexes of Eu(III) and Gd(III) with 2,2′-bipyridil are measured by spectrophotometric and luminescence methods. It is shown that luminescence of Eu(III) is quenched by Gd(III) ions at the ion concentration equal to 10?2–10?1 M, which is caused by competing between these ions for a sensitizer. At the concentration of Ln(III) ions equal to 10?6?10?3 M, the sensitized luminescence of Eu(III) and Tb(III) was quenched and τlum decreased in the presence of Nd(III) ions, whereas in the presence of Gd(III) the luminescence intensity increased. It is proved that a bridge that connects the two ions upon energy transfer is formed by hydroxyl groups. The intensity of luminescence of Eu(III) and Tb(III) in aqueous solutions and its lifetime decreased in the presence of hydroxyl groups, while upon addition of Gd(III) to these solutions these quantities were restored. We also found that the addition of Gd(III) to deoxygenated ethanol solutions of 2,2′-bipyridil and Eu(III) slows down photochemical and thermal reactions between bipyridil and Eu(III), resulting in the increase in the luminescence intensity of Eu(III). 相似文献
15.
S. B. Meshkova Z. M. Topilova M. O. Lozinskii D. V. Bol'shoi 《Journal of Applied Spectroscopy》1997,64(2):229-233
It is shown that luminescence quenching of lanthanide (Ln) ions by water molecules (OH-oscillators) entering the first coordination
sphere of a complex decreases as the chain of the fluorinated radical lengthens from CF3 to C6F13. The amounts of water molecules in binary and different-ligand Eu complexes with some fluoro derivatives of acetyl acetone
are determined. It is established that, unlike OH-oscillators, the elimination of hydrogen oscillations at the central carbon
atom by β-diketone deuteration provides the same increase (1.1–1.2 fold) in luminescence intensity in all the investigated
Eu complex compounds.
A. V. Bogatskii Physicotechnical Institute, National Academy of Sciences of Ukraine, 86, Lyustdorfskaya Read, Odessa, 270080,
Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 217–220, March–April, 1997. 相似文献
16.
G. E. Malashkevich G. P. Shevchenko Yu. V. Bokshits A. A. Kornienko P. P. Pershukevich 《Optics and Spectroscopy》2005,98(2):190-194
A record peak luminescence intensity of the 5
D
0 → 7
F
4 transition in Eu3+ ions and broadening of their UV excitation band are obtained by doping of Eu-containing alumina gel films with bismuth oxyfluoride
and subsequent thermal treatment at T ≥ 700°C. The results obtained are explained by the formation of complex Eu—Bi centers with C
3V
symmetry in the Al2O3 structure, efficient migration of excitations from EuAlO3 crystallites to these centers, and the sensitization of the luminescence of the rare-earth activator by Bi3+ ions.
__________
Translated from Optika i Spektroskopiya, Vol. 98, No. 2, 2005, pp. 224–228.
Original Russian Text Copyright ? 2005 by Malashkevich, Shevchenko, Bokshits, Kornienko, Pershukevich. 相似文献
17.
Rosa IL Oliveira LH Suzuki CK Varela JA Leite ER Longo E 《Journal of fluorescence》2008,18(2):541-545
Nowadays solid state chemists have the possibility of work with low temperature strategies to obtain solid state materials
with appropriate physical and chemical properties for useful technological applications. Photonic core shell materials having
a core and shell domains composed by a variety of compounds have been synthesized by different methods. In this work we used
silica-germania soot prepared by vapor-phase axial deposition as a core where a nanoshell of Eu2O3 was deposited. A new sol-gel like method was used to obtain the Eu2O3 nanoshell coating the SiO2–GeO2 particles, which was prepared by the polymeric precursor method. The photophysical properties of Eu3+ were used to obtain information about the rare earth surrounding in the SiO2–GeO2@Eu2O3 material during the sintering process. The sintering process was followed by the luminescence spectra of Eu3+ and all the samples present the characteristic emission related to the 5D0→7F
J
(J = 0, 1, 2, 3 and 4). The ratios of the 5D0→7F2/5D0→7F1 emission intensity for the SiO2–GeO2@Eu2O3 systems were calculated and it was observed an increase in its values, indicating a low symmetry around the Eu3+ as the temperature increases. 相似文献
18.
Tetsuo Tsuchiya Akio Watanabe Tomohiko Nakajima Toshiya Kumagai 《Applied Physics A: Materials Science & Processing》2010,101(4):681-684
Europium-doped yttrium oxide (Y2O3:Eu) thin films were successfully deposited on quartz and ITO/glass substrates by excimer-laser-assisted metal organic deposition
(ELAMOD) at low temperatures. The effects of laser wavelength and thermal temperature on the films’ crystallinity and photoluminescence
properties were investigated. Films irradiated by an ArF laser at 80 mJ/cm2 and 400–500°C were highly crystallized compared with those prepared by thermal MOD. In contrast, when the film was irradiated
by a KrF laser at 500°C, no crystalline Y2O3:Eu was formed. The Y2O3:Eu film irradiated by the ArF laser at 80 mJ/cm2 and 500°C showed typical PL spectra of Eu3+ ions with cubic symmetry and a 5D0→7F2 transition at ∼612 nm. The PL intensity at 612 nm was much higher for the film prepared with ELAMOD than for that prepared
by the thermal-assisted process, and the photoemission intensity of the film prepared with ELAMOD strongly depended on the
substrate material. 相似文献
19.
H. Nabika S. Deki 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):369-372
The effect of colloidal dispersion of silver on the
luminescent properties of Eu (III) complex with
pyridine-3,5-dicarboxylic acid (PyDC) was investigated. The
luminescence from Förster type europium complex was enhanced
several times with the presence of Ag colloid and the
enhancement factor showed Ag concentration dependence. The
observed enhancement effect was discussed in view of
surface-enhancement effect and optical absorption due to surface
plasmon resonance, both arising from excitation of surface
plasmon polariton. The coordination structure around Eu (III)
ion was also affected with the presence of Ag colloid, which
induced the change in the intensity ratio between two emission
bands of
5
D
0
7
F
1
and
5
D
0
7
F
2
transitions of Eu (III) ion. 相似文献
20.
D. V. Lapaev V. G. Nikiforov A. A. Knyazev V. I. Dzhabarov V. S. Lobkov K. M. Salikhov Yu. G. Galyametdinov 《Optics and Spectroscopy》2008,104(6):851-857
The absorption and emission spectra of a liquid-crystalline melt prepared on the basis of a synthesized mesogenic europium (III) adduct are studied in the temperature range from 77 to 348 K. The main channels and rate constants of intramolecular energy transfer from ligands to Eu (III) ions are determined from the absorption and luminescence spectra and luminescence kinetics of the sample under study. It is shown that the liquid-crystalline melt of the europium (III) adduct has a high photostability and an intense luminescence in the temperature range from 77 to 300 K, which allows one to consider it as a promising material for optoelectronic devices. Above room temperature, the relaxation time of the 5 D 0 level of Eu (III) ions sharply shortens. An analysis of the kinetics of the luminescence corresponding to the 5 D 0 → 7 F 2 transition shows that the relaxation of the 5 D 0 level in the temperature range from 300 to 348 K occurs through a charge-transfer state. 相似文献