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1.
The process of singlet—singlet resonance energy transfer between rhodamine 6G (donor) and malachite green (acceptor) has been studied with a picosecond laser : streak camera system. Unlike previous investigations, the measurements were conducted in a low viscosity solvent (ethanol) at room temperature. The donor fluorescence decay function was found to be in agreement with that predicted by the Förster theory over a tenfold range of acceptor concentrations (10?3 M to 10?2 M) and up to a limiting time resolution of 10 ps. An average R0 value of 52.5 A was obtained from the fluorescence decay curves, in reasonable agreement with the value of 48 A calculated from spectroscopic data. 相似文献
2.
The objective of this study was the investigation of energy transfer between the laser dyes rhodamine 3B (R3B) and oxazine 4 (Ox4) adsorbed on the surface of synthetic Sumecton saponite (Sum). The process of energy transfer was studied for both saponite dispersions and oriented solid films. The electronic properties, luminescence, and the energy transfer process were described by UV-vis absorption and fluorescence spectroscopy. For the efficiency of the energy transfer process, the concentrations of energy donor and acceptor components on a clay mineral surface were found to be essential. A side reaction of the molecular assembly formation reduced both the luminescence and energy-transfer yields, mainly due to fluorescence quenching. The quenching was more problematic for the solid film specimens, where an appropriate modification of the inorganic host with hydrophobic alkylammonium cations was used to achieve a higher luminescence. Due to the higher tendency of Ox4 to form nonluminescent aggregates at higher concentrations, the lowering of the Ox4 concentration further improved the luminescent properties of the films. In this case, the energy transfer occurring in the solid film from R3B to Ox4 was clearly proven. 相似文献
3.
罗丹明6G的荧光光谱 总被引:1,自引:0,他引:1
在苯-甲醇混合溶剂中测量了罗丹明6G的吸收光谱和荧光光谱,发现体系中荧光强度和光密度随甲醇浓度的增长而增长.这可解释为甲醇浓度增加,溶液的介电常数也增加,这样自由离子浓度增加,未解离分子浓度减少.结果表明无论由吸收光谱和由荧光光谱都说明荧光来源于R6G离子. 相似文献
4.
The energy transfer between rhodamine-6G and 3,3′-diethylthiacarbocyanine iodide was studied in aqueous solutions of sodium lauryl sulfate. A highly enhanced energy transfer was observed at very low dye concentrations in the premicellar region. This effect can be explained in terms of the formation of dye-rich mixed micelles. 相似文献
5.
Yu-Qian Yan Xian Tang Yong-Sheng Wang Ming-Hui Li Jin-Xiu Cao Si-Han Chen Yu-Feng Zhu Xiao-Feng Wang Yan-Qin Huang 《Mikrochimica acta》2015,182(7-8):1353-1360
6.
Saini GS Kaur S Tripathi SK Mahajan CG Thanga HH Verma AL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(4):653-658
We report here electronic absorption, fluorescence and resonance Raman studies of rhodamine 6G laser dye dispersed in the polymethylcyanoacrylate matrix. In the electronic absorption and fluorescence spectra of dispersed rhodamine 6G, band maxima are red shifted compared to solution. Raman spectra show some new bands. These spectral changes arise due to matrix effect and interaction between rhodamine 6G and the host material involving amine group of rhodamine. 相似文献
7.
In this paper we present the results of an experimental study of intermolecular electronic energy transfer (EET) from the short-lived Second excited singlet state of rhodamine 6G (R6G) to the ground state of 2,5-bis [5′-tert-butyl-2-benzoxazolyl] thiophene (BBOT). The S2 state of the donor was excited by sequential, time-delayed, two-photon excitation (STDTPE) utilizing the second harmonic and the first harmonic of a mode-locked Nd3+: glass laser, while the EET process was interrogated by monitoring the enhancement of the S1 → S0 fluorescence of BBOT. The enhancement of the fluorescence intensity of BBOT was found to be linear in the energies of the two exciting pulses, and linear in the concentration of the energy acceptor (over the BBOT concentration range of (0.3–7) × 10?5 M), which is in accord with the predictions of the Forster—Dexter mechanism for resonant EET from an ultrashort-lived donor state at low acceptor concentrations. Quantitative measurements of the S2 → S0 fluorescence yield in R6G solution directly excited by STDTPE and of the S1 → S0 fluorescence of BBOT from R6G + BBOT solutions resulting from EET led to the values of YD(S2 → S0) = (2.1 ± 0.5) × 10?6 for the emission quantum yield of the S2 state of R6G and τrD(S2) ≈ 3 × 10?14 s for the lifetime of the metastable S2 state of this molecule. 相似文献
8.
Stopped-flow mixing device and visible absorption spectroscopy were used for the analysis of dye rhodamine 6G (R6G) molecular aggregation in the colloids based on Na-saturated montmorillonite. Two stages of the reaction were identified: The first stage was very short and taking only several seconds, involving the adsorption of R6G cations and their initial aggregation on the surface of colloid particles. The initially formed J-aggregates exhibited similar spectral properties as monomeric form of R6G. In the second stage, initially formed aggregates converted to sandwich-type H-aggregates absorbing light at significantly lower wavelengths and adsorbed monomers. The aggregate rearrangement took several hours. Monomers, with the spectral properties identical to R6G solution, were also identified as a component in complex spectra using principal component analysis (PCA) and multivariate curve resolution (MCR). Partial bleaching of the dye was also proven. Reaction kinetics of the rearrangement of the aggregates followed the model considering a complex mechanism of the molecular aggregation. Data fits using stretched-exponential function led to the determination of rate constants, which had been in the range 10?3?4×10?3s?1. 相似文献
9.
Hengguo Wang Qingbiao Yang Lei Sun Shuai Wang Wei Wang Chaoqun Zhang Yanchun Li Shufei Xu Yaoxian Li 《Journal of colloid and interface science》2010,341(2):224-231
Novel fluorescent composite nanofibrous films of rhodamine 6G (Rh6G) and polyacrylonitrile (PAN) are first prepared by electrospinning. The aggregation states of Rh6G in electruspun nanofibrous films are studied as a function of concentrations and characterized by UV–vis absorption spectroscopy and emission and excitation fluorescence spectroscopy. We have also used casting films as reference material to compare the effect of incorporation of Rh6G in electrospun nanofibrous films and casting films. The large specific surface area of the nanofibers and fast evaporation of the solvents in the electrospinning process reduced the aggregation of Rh6G. The appearance of fluorescent J-type dimers, even at higher dye concentration in elctrospun films, demonstrates that the electrospun films are an ideal material for incorporation of fluorescent dyes. 相似文献
10.
P Wormald B Lundgren K Andersson J W DePierre 《Acta chemica Scandinavica (Copenhagen, Denmark : 1989)》1992,46(1):100-102
Upon interaction of various glycerophospholipids with Rhodamine 6G in toluene, a typical difference spectrum with an absorption maximum at approximately 515 nm is obtained . This spectrum is obtained with phosphatidylcholine only after treatment with NaCl, which presumably weakens intra- and/or inter-molecular electrostatic binding between the negatively charged phosphate moiety and the protonated nitrogen in this molecule. Absorption at 515 nm was linear for all of the phospholipids investigated from a concentration of approximately 1.2 microM up to at least 50 microM. The highest extinction coefficient was obtained for diphosphatidylglycerol (251 mM-1 cm-1) and all of the compounds tested, with the exception of phosphatidylethanolamine, demonstrated extinction coefficients higher than that of palmitic acid. Thus, the absorption spectrum which results from the interaction of purified glycerophospholipids with Rhodamine 6G in organic solvent is a sensitive measure of the amount of phospholipid present. 相似文献
11.
By coupling flow-injection with laser-induced fluorescence detection, a setup was developed and a novel method combining fluorescence resonance energy transfer (FRET) and flow-injection analysis (FIA) was proposed for the determination of vitamin B12 (VB12) based on its fluorescence quenching on the system of acridine orange (AO)/rhodamine 6G (R6G). The effective energy transfer could occur between AO and R6G in the dodecyl benzene sodium sulfonate (DBS) while 454 nm argon laser was used as the excitation source, and as a result, the fluorescence emission of R6G has been increased significantly. It was found that the fluorescence of the above system could be sharply diminished by VB12. By using the mixed solution AO-R6G-DBS and the same solution containing VB12 as the carrier and sample, respectively, a series of negative peaks which could be applied for the quantification of VB12 were obtained. The detection limit for VB12 was 1.65 × 10−6 mol/L. The linear range for determining VB12 was 4 × 10−4 to 2 × 10−6 mol/L (correlation coefficient, r = 0.9923). The method was applied to measure VB12 injections with satisfactory results. 相似文献
12.
Vogel R Meredith P Harvey MD Rubinsztein-Dunlop H 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(1-2):245-249
A comparison has been made between the spectroscopic properties of the laser dye rhodamine 6G (R6G) in mesostructured titanium dioxide (TiO(2)) and in ethanol. Steady-state excitation and emission techniques have been used to probe the dye-matrix interactions. We show that the TiO(2)-nanocomposite studied is a good host for R6G, as it allows high dye concentrations, while keeping dye molecules isolated, and preventing aggregation. Our findings have important implications in the context of solid state dye-lasers and microphotonic device applications. 相似文献
13.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1991,47(2):211-217
A new experimental technique has been developed whereby the observation of the absorption bands due to the tetrameric species of rhodamine 6G in ethanolic solutions could become possible for the first time. The excitonic treatment of the electronic data backed by the 1H NMR and vibrational studies suggest a coplanar structure for the dimers whereas the interaction between the parallel planes at a twisted angle of θ = 108° can constitute the tetrameric aggregates. The nature of the transitions involved in the absorption spectra are shown to be vibronic. The symmetry considerations have therefore been taken into account in order to ascertain the validity of the proposed structure for the tetramers. 相似文献
14.
We have observed Stokes and anti-Stokes emission of Au nanoparticles suspended in methanol and rhodamine 6G dye solution. Photoluminescence of Au nanoparticles is a three-step process involving single-photon or three-photon excitation of electron-hole pairs, relaxation of excited electrons and holes, and emission from electron-hole recombination, possibly enhanced by surface plasmons. In the presence of dye, the excitation of anti-Stokes emission of gold involves two-photon absorption in rhodamine 6G molecules followed by the energy transfer to Au nanoparticles with simultaneous absorption of one pumping photon by Au. This mechanism significantly enhances anti-Stokes emission of gold nanoparticles in the presence of dye. 相似文献
15.
The reaction of the uranium-anthranilic acid complex to form an ion-association complex with Rhodamine 6G provides a means for its estimation. The anionic primary complex is suggested to be a mixed-ligand complex of uranium with anthranilic acid and its oxidation products. The method is sensitive ( = 6.25 x 10(4) 1.mole(-1).cm(-1) at 575 nm) and fairly selective, and obeys Beer's law for 0.04-4.00 ppm of uranium. It has been applied to analysis of monazite sand. 相似文献
16.
P. Bojarski A. Matczuk C. Bojarski A. Kawski B. Kukliński G. Zurkowska H. Diehl 《Chemical physics》1996,210(3):485-499
Aggregation of rhodamine 6G in concentrated ethylene glycol solutions is studied as a function of temperature. The measurements of absorption and fluorescence spectra evidence that the system of interest consists of two fluorescent species: monomers and dimers. Strong overlaps between all absorption and fluorescence bands in this system enable forward and reverse energy transport between monomers and dimers. The quantitative analysis of the effect of nonradiative energy transport (NET) on the fluorescence spectra as well as on the fluorescence quantum yields of monomers and dimers explains the temperature and concentration regularities observed. In particular, it is shown that in the concentrated solution the calculated monomer quantum yield is underrated compared to that measured, if the reverse NET is neglected. The lack of information on the value of the dimer quantum yield does not allow for full analysis of the forward and reverse NET in the system. However, it is shown that if that quantum yield is determined as the best fit parameter, an excellent agreement between the experimental and calculated values is obtained. 相似文献
17.
《Chemical physics letters》1987,134(6):605-609
Transient behavior of the fluorescence spectrum has been investigated in rhodamine 6G in ethanol at low temperatures by means of a time-resolved luminescence technique. The width of the fluorescence spectrum as well as its peak position has been found to change with time. These characteristics are shown to be well explained by a stochastic model. 相似文献
18.
Kievsky YY Carey B Naik S Mangan N ben-Avraham D Sokolov I 《The Journal of chemical physics》2008,128(15):151102
We describe a method to study diffusion of rhodamine 6G dye in single silica nanochannels using arrays of silica nanochannels. Dynamics of the molecules inside single nanochannel is found from the change of the dye concentration in solution with time. A 10(8) decrease in the dye diffusion coefficient relative to water was observed. In comparison to single fluorescent molecule studies, the presented method does not require fluorescence of the diffusing molecules. 相似文献
19.
Sathrugnan Kartikeyan Talasila Prasada Rao Chonatumaton S. P. Iyer Alathur D. Damodaran 《Mikrochimica acta》1993,111(4-6):193-198
A simple and highly selective spectrophotometric method is described for the determination of nitrite. The method is based on the measurement of decrease in absorbance at 525 nm of rhodamine 6 G in sulphuric acid medium. The decrease in absorbance is instantaneous on addition of nitrite and remains stable for 2 h. Linear calibration graph passing through the origin was obtained in the range 0.01–0.6 g/ml nitrite. The method is free from interference of Cu2+, Fe3+ and SO
3
2–
which normally interfere in other procedures. The method was applied successfully to the determination of nitrite in well and sea water samples and in KNO3, NaNO3, table salt, sugar and milk powder samples. 相似文献
20.
The rotational diffusion time constants of rhodamine 6G in water, cetyldimethylbenzylammonium chloride, and sodium dodecylsulfate micellar solution has been determined with a picosecond phase fluorimeter in the temperature range 10°C to 80°C. Data analysis shows a strong micellar influence leading to anisotropic rotational diffusion in sodium dodecylsulfate micellar solution. 相似文献