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1.
We study the sensitization of fluorescence of Nile red in nanoparticles formed in aqueous solutions of complexes of Al, In,
Sc, and Lu with DBM, DBM, and phen and of complexes of In with MBTA and phen. We show that, at concentrations of Nile red
of 2–50 nM and complexes of 10–30 μM, the fluorescence intensity of Nile red in aqueous solutions increases by 1.5–2 orders
of magnitude compared to its fluorescence in H2O. We find that, at these concentrations of Nile red in solutions of complexes Al, the dye is completely contained in nanoparticles
from these complexes. We show that Nile red molecules are inhomogeneously distributed in nanoparticles from complexes and,
upon the completion of the formation of nanoparticles, dye molecules tend to be localized in regions of nanoparticles formed
from diketonate complexes M(diketone)3phen (M is Lu or In) and Al(DBM)3. Upon the localization of Nile red in these regions, the maximum of its fluorescence spectrum shifts toward ∼600 nm and,
upon the penetration of Nile red into nanoparticles from Sc complexes, the shift of the maximum of its fluorescence spectrum
compared to the spectrum in water does not exceed 10 nm. The shifts of the spectra are collated with the ability of ions to
form diketonate and hydroxy diketonate complexes. We demonstrate that the fluorescence of Nile red is efficiently sensitized,
not only upon its penetration into nanoparticles formed from complexes, but also upon its adsorption on the nanoparticle surface
when Nile red molecules are introduced in solutions of already formed nanoparticles. 相似文献
2.
The fluorescence and absorption spectra of Rose Bengal dye in aqueous solution have been studied in the presence of various nonionic, anionic and cationic surfactants. With cationic and nonionic surfactants, shifts occur in the absorption and emission peaks of the dye solution, with a large enhancement in the absorption and fluorescence intensity at the shifted λmax. No appreciable change in the absorption and fluorescence spectra of the dye has been observed on the addition of anionic surfactants.All the changes observed in the absorption and fluorescence spectra of the dye solution with surfactants may be attributed, to binding of the surfactant with dye molecules and the disaggregation of the dye multimer forms into the monomeric form. 相似文献
3.
O. V. Ovchinnikov E. A. Kosyakova L. Yu. Leonova M. S. Smirnov A. B. Evlev A. N. Latyshev A. N. Utekhin 《Russian Physics Journal》2008,51(3):244-250
The sensitized anti-Stokes luminescence excited by radiation with wavelengths from 610 to 750 nm and flux densities of 1014–1015 quanta/(cm2·s) is detected for microcrystals of Zn
0.6
Cd
0.4
S solid solutions with adsorbed organic malachite green and methylene blue dye molecules. The position of its excitation spectra
coincides with that of the absorption spectra of adsorbed dye molecules, which suggests the cooperative mechanism of its occurrence.
The possibility of amplification of the anti-Stokes luminescence by means of adsorption of silver atoms and few-atomic silver
clusters, in addition to the dye molecules, on the Zn
0.6
Cd
0.4
S surface is investigated. It is assumed that in the latter case, the anti-Stokes luminescence is excited as a result of two-quantum
optical transitions with electron or electron excitation energy transfer from the dye molecules adsorbed on the Zn
0.6
Cd
0.4
S surface to silver atoms and few-atomic silver clusters creating deep local states with photoionization energies of 1.8–2.0
eV in the gap.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 21–26, March, 2008. 相似文献
4.
V. A. Svetlichnyi M. P. Samtsov O. K. Bazyl’ O. V. Smirnov D. G. Mel’nikov A. P. Lugovskii 《Journal of Applied Spectroscopy》2007,74(4):524-532
We present results of experimental and theoretical studies of the optical characteristics of a new indotricarbocyanine dye
that is capable of effectively limiting the power of laser radiation in the visible spectral range. The spectral-luminescent
and energy characteristics of the dye molecules and their absorption spectra from the excited state with nanosecond resolution
are investigated experimentally. Quantum-chemical methods are used to calculate electronic absorption spectra from the ground
(S0 → Sn) and excited (S1 → Sn) states and to determine the nature of electronic states of the molecule and the rate constants of intramolecular photophysical
processes. The results of the theoretical research agree with experimental data. It is shown that the investigated dye has
singlet-singlet absorption at 400–600 nm. Nonlinear absorption of the dye upon excitation by radiation of the second harmonic
of a Nd:YAG laser is studied by z-scanning with an open diaphragm. The ratio of dye absorption cross sections from the excited
and ground states at 532 nm is determined in the framework of a three-level model. The results are compared with those for
previously studied compounds.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 473–480, July–August, 2007. 相似文献
5.
M. P. Samtsov S. A. Tikhomirov O. V. Buganov K. N Kaplevsky D. G. Melnikov L. S. Lyashenko 《Journal of Applied Spectroscopy》2009,76(6):783-790
Spectral-kinetic and photochemical properties of HITC dye with iodide and perchlorate counterions have been studied in environments
where the dye molecules exist in different ionic forms. In ethanol, the dye molecules exist as free ions; in dichlorobenzene,
as contact ion pairs. Superfast transformation of non-stationary spectra in an HITC dye bleaching band is found. The observed
effects are interpreted within the framework of concepts on “burning out” a notch in the contour of a non-uniformly widened
vibronic band of S
0 → S
1-absorption. Qualitative differences in recorded absorption spectra from the dye excited electronic states for weakly and
highly polar solvents are found. It is shown that the observed differences are caused by superfast charge transfer in the
contact ion pairs that results in the formation of free radicals. 相似文献
6.
T. Sh. Éfendiev V. M. Katarkevich A. N. Rubinov A. P. Stupak 《Journal of Applied Spectroscopy》2001,68(1):124-129
We present the results of comparative measurements of spectral–luminescent characteristics of Rhodamine 6G and Rhodamine C in water and water–gelatin solutions. We found that gelatin added to a water solution disaggregates the molecules of the dye. The maxima of the absorption and luminescence spectra of the solution shift then to the longwave region. The quantum yield of luminescence and the efficiency of generation of the solutions investigated are measured. The generation intensity of the gel is shown to depend on its composition and the dye selected. Measurement of spectral–luminescent characteristics of water–gelatin solutions makes it possible to select dyes that would generate most efficiently in gel solutions. 相似文献
7.
Langmuir-Blodgett (LB) films formed of some fluorescent dyes, namely derivatives of 4-aminonaphthalimide, and their binary
mixtures with the liquid crystal 4-heptyl-4′-cyanobiphenyl (7CB) have been studied. The electronic absorption and fluorescence
spectra were recorded. On the basis of these spectra, the spectral properties of the dyes and the intermolecular interactions
in ultrathin ordered films were determined. The conclusions about the tendency to the creation of aggregates by dye molecules
in LB films have been drawn. The measurements of absorption by using linearly polarised light have allowed us to determine
the arrangement of the dye and liquid crystal molecules on the air-solid substrate interface. 相似文献
8.
O. V. Ovchinnikov S. V. Chernykh M. S. Smirnov D. V. Alpatova R. P. Vorob’eva A. N. Latyshev A. B. Evlev A. N. Utekhin A. N. Lukin 《Journal of Applied Spectroscopy》2007,74(6):809-816
We have used IR spectroscopy to study the nature of interaction between molecules of the organic dye methylene blue (MB) and
the surface of AgCl(I) microcrystals. We recorded the IR absorption spectra of the organic dye methylene blue in the gas phase,
adsorbed on the surface of AgCl(I) microcrystals, and also in the form of crystal hydrates. The results obtained allowed us
to hypothesize that unsaturated dimethylamino groups and the sulfur atom in the heterocycle of this dye are the most active
in the interaction between methylene blue molecules and the surface of AgCl(I) microcrystals. With the help of IR spectra
of methylene blue crystal hydrates, we confirmed the significant role of OH groups during adsorption of molecules on the surface
of AgCl(I) microcrystals. We suggest the possibility of formation of hydrogen bonds between the anions of the crystal lattice
and the unsaturated dimethylamino groups as well as the sulfur atoms in the heterocycle, by formation of hydrogen bonds with
the OH groups.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 731–737, November–December, 2007. 相似文献
9.
Optical characterization of sol gel TiO<Subscript>2</Subscript> monoliths doped with Brilliant Green
S. A. Tomás O. Zelaya R. Palomino R. Lozada O. García J. M. Yáñez A. Ferreira da Silva 《The European physical journal. Special topics》2008,153(1):255-258
Amorphous titanium dioxide monoliths doped with brilliant green (BG) were synthesized by the sol-gel process. The optical
properties of the monoliths were characterized by Photoacoustic Spectroscopy and Photoluminescence Spectroscopy. The absorption
spectra for the BG-doped TiO2 monoliths exhibited two well defined absorption regions: a band below 400 nm corresponding to TiO2 absorption and three absorption bands centered at 424 nm, 588 nm, and 632 nm due to brilliant green. While the undoped TiO2 monoliths showed no luminescence, the doped samples showed a strong luminescence band at 673 nm, which increased its intensity
for increasing organic dye doping. 相似文献
10.
The transmission spectra of Rhodamine B and Rhodamine 6G dyes coated on silver island films for various thickness were recorded.
A strong coupling between the silver particle plasma resonance and the dye molecules is observed. The absorption of dye molecules
increases when the absorption band of individual dyes and silver particles overlaps. In higher silver film thicknesses, transmission
increases. The theoretical calculation using Maxwell-Garnett theory and Wang and Kerker’s results qualitatively supports the
observed phenomenon. A red shift in the absorption peak of dyes on silver surfaces in comparison to solution phase absorption
peak indicates photobleaching. 相似文献
11.
O. V. Ovchinnikov E. A. Kosyakova M. S. Smirnov A. B. Evlev V. G. Klyuev A. N. Latyshev A. N. Utekhin 《Journal of Applied Spectroscopy》2007,74(5):681-686
For microcrystals of Zn0.6Cd0.4S with adsorbed molecules of a number of organic dyes, we have observed sensitized anti-Stokes luminescence excited by radiation
with wavelengths in the range 610–750 nm and flux density 1014–1015 photons/cm2·sec. The positions of the bands in the excitation spectra for such luminescence match those of the absorption spectra for
the adsorbed dye molecules, which is evidence in favor of a cooperative mechanism for its appearance. We have shown that enhancement
of the anti-Stokes luminescence is possible when silver atoms and few-atom clusters appear on the Zn0.6Cd0.4S surface in addition to the dye molecules. We hypothesize that its excitation in the latter case occurs as a result of two-photon
optical transitions. These transitions occur sequentially, with transfer of an electron or the electronic excitation energy
from the dye molecules to silver atoms and few-atom clusters adsorbed on the surface of Zn0.6Cd0.4S, creating deep localized states in the bandgap with photoionization energies 1.80–2.00 eV.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 617–621, September–October, 2007. 相似文献
12.
电压敏感染料di-4-ANEPPS的光谱研究 总被引:3,自引:3,他引:0
实验研究了电压敏感染料di-4-ANEPPS在家兔心肌组织中的吸收光谱和荧光光谱特性。结果表明,含染料组织的光吸收普遍大于对照组,在450~550 nm波段吸收谱差异更明显;染料在心室组织中的最大吸收峰为(479.75±0.44) nm。通过测量含染料心脏不同部位的荧光光谱,首次发现心室组织、心房组织和主动脉的最大荧光峰位有一定差异,其相对荧光强度则与染料的分布浓度有关。根据三维和二维荧光光谱分别确定了含染料心房和心室组织的最佳荧光激发波长和荧光测定波长。利用心房和心室组织的静息电位差,在不同波长激发光下测量了染料的荧光光谱移动,确定了光标测量实验的最佳激发光和相应荧光检测波长范围。这些研究结果为心脏光学标测系统的设计提供了理论依据。 相似文献
13.
We have studied the pore size dependences of association processes for dye molecules incorporated into the matrix of a porous
silicate glass. We have determined the structures of the associates of dye molecules as a function of the type of dye, the
dye concentration, and the matrix pore sizes. We have established a nonuniform distribution of the complex dye molecules in
the porous glass matrix, which is responsible for the higher efficiency of the association processes for the adsorbed molecules
compared with alcoholic solutions of these dyes.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 824–827, November–December, 2006. 相似文献
14.
Hybrid nanomaterials were synthesized by adopting femtosecond laser ablation of a ZnO target in pure ethanol. Dye molecules were grafted onto the ZnO nanoparticles by mixing colloidal ZnO-ethanol solution prepared by laser ablation to Tetramethylrhodamine B isothiocyante, or to Rhodamine B solutions. Strongly facetted nanohybrid particles were observed with an average size of 15 nm, by HRTEM measurements. From photoluminescence spectroscopy of the nanohybrids after single and multiphoton excitations, we observed energy transfer from the ZnO nanoparticles towards the attached dye molecules. Moreover, IR excitation spectra of the hybrid nanomaterials reveal the emission of the grafted dye via two photon absorption of the ZnO. 相似文献
15.
A study of azo dye/liquid crystal mixtures in monolayers formed at air-water (Langmuir films) and air-solid substrate (Langmuir-Blodgett
films) interfaces was performed. Three azo dyes with various molecular structure and two liquid crystal materials: 4-octyl-4′-cyanobiphenyl
(8CB) and trans-4-octyl(4′-cyanophenyl)-cyclohexane (8PCH) were used. The morphology of Langmuir films was monitored by means
of a Brewster angle microscope (BAM). Moreover, a surface pressure and electronic absorption spectra of the monolayer spread
on the water surface of dye/liquid crystal mixtures as a function of a mean molecular area were simultaneously recorded. In
addition, the absorption for Langmuir-Blodgett films deposited on quartz plates was measured. Information about intermolecular
interactions in the mixtures of the nonamphiphilic dye and the liquid crystal with polar terminal group was obtained. Conclusions
about the formation of self-aggregates between dye molecules have been drawn. The influence of the dye molecular structure
and its concentration on aggregates’ geometry was found. 相似文献
16.
We studied the dependence of absorption and fluorescence spectra of complexes of Al, In, Sc, Y, and La with dibenzoylmethane
and naphthoyltrifluoroacetone, as well as the dependence of sensitized fluorescence of dyes in nanoparticles of these complexes,
in relation to the water pH, the ratio between ions and diketones, and the ion selection. We showed that the ability of complexes
of ions to form nanoparticles that efficiently sensitize dye molecules incorporated into them is determined by stability constants
of these ions with organic ligands and by their ability to compete with the formation of hydroxy complexes of these ions.
We found that nanoparticles consist of diketonates of different compositions and that Nile red incorporated into nanoparticles
is an indicator of the dependence of the composition of nanoparticles on the selection of the central ion of complexes and
conditions of their formation. We revealed that complexes M(diketone)(OH)2 self-assemble into nanoparticles with an admixture of dye molecules and efficiently sensitize dyes upon excitation into absorption
bands of complexes. We showed that, at concentrations of rhodamine 6G in water smaller than 50 nM, the use of a solution that
contains 50 μM of Al(III), In(III), or Sc(III) + 50 μM of naphthoyltrifluoroacetone makes it possible to increase the sensitivity
of the luminescence analysis by 20-fold for the presence of rhodamine 6G in an aqueous solution. 相似文献
17.
We measured the optical absorption spectra of para-benzoquinone and duroquinone in polar (methanol) and nonpolar (n-hexane) solvents. We find that the specific effect of the polar solvent, which manifests itself here as a bathochromic shift
of one of π-π* bands, is caused by the formation of hydrogen bonds between solvent molecules and the molecule under study
and, as a consequence, by a decrease in the energy gap between the corresponding occupied (π) and unoccupied (π*) molecular
orbitals. This result is obtained by TDDFT B3LYP/6-311+G(d, p)-calculations of electronic spectra, which, in the case of isolated
para-benzoquinone and duroquinone molecules, reproduce experimental optical absorption spectra of the corresponding compounds
in n-hexane and, in the case where these molecules form complexes with methanol molecules by means of hydrogen bonds, reproduce
spectra measured in methanol. 相似文献
18.
D. V. Ageev S. V. Patsaeva B. D. Ryzhikov V. N. Sorokin V. I. Yuzhakov 《Journal of Applied Spectroscopy》2008,75(5):653-657
The effect of temperature on absorption spectra of Rhodamine 6G at concentrations of 10−6 and 10−3 M in water:ethanol solutions of various ethanol content was studied. The dimeric molecular fraction of Rhodamine 6G (10−3 M) was found as a function of temperature and ethanol content in the aqueous solution. It was shown that the absorption spectrum
of Rhodamine 6G dimers (10−3 M) is dependent on temperature and ethanol content in the aqueous solution. Based on the relationship between J-and H-bands
in the absorption spectrum of Rhodamine 6G dimers, both the angle between planes of associated Rhodamine 6G dye molecules
and the free enthalpy of association were calculated. The structure of Rhodamine 6G dimers depends essentially on the ethanol
content and aqueous ethanol solution temperature while experiencing the most temperature changes at an ethanol concentration
of 25%.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 640–645, September–October, 2008. 相似文献
19.
E. V. Dubrovskaya T. D. Kolomiitsova A. V. Shurukhina D. N. Shchepkin 《Optics and Spectroscopy》2016,120(2):223-234
In the IR absorption spectra of low-temperature molecular liquids, we have observed anomalously large isotope shifts of frequencies of vibrational bands that are strong in the dipole absorption. The same effect has also been observed in their Raman spectra. At the same time, in the spectra of cryosolutions, the isotope shifts of the same bands coincide with a high accuracy (±(0.1–0.5) cm–1) with the shifts that are observed in the spectra of the gas phase. The difference between the spectra of examined low-temperature systems is caused by the occurrence of resonant dipole–dipole interactions between spectrally active identical molecules. The calculation of the band contour in the spectrum of liquid freon that we have performed in this work taking into account the resonant interaction between states of simultaneous transitions in isotopically substituted molecules can explain this effect. 相似文献
20.
Samira Ceccarelli Jakub Wenus Maurice S. Skolnick David G. Lidzey 《Superlattices and Microstructures》2007,41(5-6):289
We investigated the absorption and photoluminescence (PL) of J-aggregates of a cyanine dye both in a thin film format and when used as the active layer in a strongly-coupled microcavity. We show that as temperature is reduced, the absorption linewidth of the J-aggregates narrows and shifts to higher energy. When the J-aggregate is placed in a microcavity we find that the energy of the polariton modes also shifts to higher energies as temperature is reduced. We compare the intensity of PL emission from the upper and lower branches at resonance as a function of temperature, and find that it can be described by an activation energy of 25 meV. PL emission spectra at resonance also suggest that uncoupled excitons inside the microcavity populate the upper polariton branch states. 相似文献