Detail of "70504-01-7"

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Resolution of multicomponent fluorescence emission by phase sensitive detection at multiple modulation frequencies

Resolution of multicomponent fluorescence emission by phase sensitive detection at multiple modulation frequencies. Keating-Nakamoto, Susan M.Some chemicals with cas registry numbers like 1948-71-6 and 70504-01-7 are also used.; Cherek, Henryk; Lakowicz, Joseph R. (Sch. Med., Univ. Maryland, Baltimore, MD 21201, USA). Anal. Chem., 59(2), 271-8 (English) 1987. CODEN: ANCHAM. ISSN: 0003-2700. DOCUMENT TYPE: Journal CA Section: 73 (Optical, Electron, and Mass Spectroscopy and Other Related Properties) Section cross-reference(s): 22 Phase sensitive emission spectra recorded at multiple frequencies were used to det. the lifetimes and steady-state spectra of the fluorophores in 2-component mixts. This anal. does not require any previous knowledge of the lifetimes, fractional intensities, or emission spectra and is an improvement over single frequency phase sensitive detection which requires known emission spectra or lifetimes. Phase sensitive emission spectra are recorded at several frequencies and arbitrarily chosen detector phase angles. The data are analyzed by use of nonlinear least squares to recover the lifetimes and wavelength-dependent fractional intensities. The latter values det. the emission spectrum and relative intensity of each component in the mixt. Two-component mixts. were resolved of fluorescein and 9-aminoacridine, 2-(p-toluidinyl)naphthalene-6-sulfonic acid and 6-propionyl-2-(dimethylamino)naphthalene, and N-acetyl-L-tyrosinamide and N-acetyl-L-tryptophanamide. In these mixts. the lifetimes differ by ~2-fold. Anal. of simulated data is presented to illustrate the requirements for a satisfactory resoln. For simulated 2-component mixts., the components can be resolved if the lifetimes differ by 32-fold, even with extensive overlap of the emission spectra. .

New Insights on the Photophysical Behavior of PRODAN in Anionic and Cationic Reverse Micelles: From Which State or States Does It Emit?

All Rights Reserved. New Insights on the Photophysical Behavior of PRODAN in Anionic and Cationic Reverse Micelles: From Which State or States Does It Emit?. Novaira, Mercedes; Biasutti, M.Several substances are used for example 122-18-9 and 70504-01-7 which are their cas registry numbers. Alicia; Silber, Juana J.; Correa, N. Mariano (Departamento de Quimica, Universidad Nacional de Rio Cuarto, Rio Cuarto X5804ALH, Argent.). Journal of Physical Chemistry B, 111(4), 748-759 (English) 2007 American Chemical Society. CODEN: JPCBFK. ISSN: 1520-6106. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) Section cross-reference(s): 66, 74 6-Propionyl-2-(N,N-dimethyl)aminonaphtahalene, PRODAN, is widely used as a fluorescent mol. probe because of its significant Stokes shift in polar solvents. It is an arom. compd. with intramol. charge-transfer states (ICT) that can be particularly useful as a sensor. The nature of the emissive states has not yet been established despite the detailed exptl. and theor. investigations done on this fluorophore. In this work, we performed absorption, steady-state, time-resolved fluorescence (TRES) and time-resolved area normalized emission (TRANES) spectroscopies on the mol. probe PRODAN in the anionic water/sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/n-heptane and the cationic water/benzyl-n-hexadecyldimethylammonium chloride (BHDC)/benzene reverse micelles (RMs). The expts. were done by varying the surfactant concns. at a fixed molar ratio (W = [H2O]/[Surfactant]) and changing the water content at a const. surfactant concn. The results obtained varying the surfactant concn. at W = 0 show a bathochromic shift and an increase in the intensity of the PRODAN emission band due to the PRODAN partition process between the external solvent and the RMs interface. The partition consts., Kp, are quantified from the changes in the PRODAN emission spectra and the steady-state anisotropy () with the surfactant concn. in both RMs. The Kp value is larger in the BHDC than the AOT RMs, probably due to the interaction between the cationic polar head of the surfactant and the arom. ring of PRODAN. The partition process is confirmed with the TRES expts., where the data fit to a continuous model, and with the time-resolved area normalized emission spectroscopy (TRANES) spectra, where only one isoemissive point is detected. On the other hand, the emission spectra at W = 10 and 20 show a dual fluorescence with a new band that emerges in the low-energy region of the spectra, a band that was previously assigned to the PRODAN emission from the water pool of RMs. Our studies demonstrate that this band is due to the emission from an ICT state of the mol. probe PRODAN located at the interface of the RMs. These results are also confirmed by the lifetime measurements, the TRES expts. where the results fit to a two-state model, and the time-resolved area normalized emission spectroscopy (TRANES) spectra where three or two isoemissive points are detected in the AOT and BHDC RMs, resp. In the AOT RMs, Kp values obtained at W = 10 and 20 are almost independent of the water content; the values are higher for the BHDC RMs due to the higher micropolarity of this interface. .