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Z. Phys. Chem. 225 (2011) 1055–1072 / DOI 10.1524/zpch.2011.0149 © by Oldenbourg Wissenschaftsverlag, München Characterization of Rhodamine 6G Release in Electrospray Ionization by Means of Spatially Resolved Fluorescence Spectroscopy By Daniel Riebe, Martin Zühlke, Karl Zenichowski, Toralf Beitz, Carsten Dosche, and Hans-Gerd Löhmannsröben∗ Universität Potsdam, Physikalische Chemie, Karl-Liebknecht-Str. 24–25, Haus 25, 14476 Potsdam-Golm, Germany Dedicated to Prof. Horst Hippler on the occasion of his 65th birthday (Received July 8, 2011; accepted in final form

of laser properties of pyrromethene 567 dye incorporated into new organic-inorganic hybrid materials”, Chem. Phys. Lett., Vol. 369, (2003), pp. 656–661. http://dx.doi.org/10.1016/S0009-2614(03)00021-6 [5] T. Suratwala, Z. Gardlund, K. Davidson, D.R. Uhlmann J. Watson, S. Bonilla and N. Peyghambarian: “Silylated Coumarin Dyes in Sol-Gel Hosts”, Vol. 10, (1998), pp. 199–209. [6] D. Avnir, D. Levy and R. Reisfeld: “The Nature of Silica Cage as Reflected by Spectral Changes and Enhanced Photostability of Trapped Rhodamine 6G”, J. Phys. Chem., Vol. 88, (1984), pp. 5956

Abstract

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.

Abstract

This paper describes the preparation and characterization of poly(ethyl cyanoacrylate) colloidal particles loaded with the organic fluorophore Rhodamine 6G. We studied the physicochemical properties of the colloidal particles: morphology, size-distribution, ζ-potential, fluorescent properties and photobleaching upon UV-light illumination. The properties of the obtained colloidal particles, as well as the dye loading efficiency, were found to depend on the concentrations of ethyl cyanoacrylate monomer and Rhodamine 6G in the polymerization medium. The fluorophore release from the colloidal particles in aqueous buffer is also studied.

W/ XWV Triplet Quenching by Oxygen in a Rhodamine 6G Laser F. P. Schäfer and L. Ringwelski Max-Planck-Institut für Biophysikalische Chemie, Göttingen, BDR (Z. Naturforsch. 28 a. 792-793 [1973] ; received 10 March 1973) Measurements of dye laser output power vs. oxygen content of the dye solution are reported and compared with a simple theoretical model. The triplet lifetime of rhodamine 6G in oxygen-free methanol at room temperature is seen to lie be­ tween 1 and 100//sec, with 2 /<sec giving the best fit of the experimental data. Triplet

nanoform and have been synthesized after the frustules have been harvested, thereby leading to differential distribution of the metal oxides on the diatomite [ 33 ]. Even though these composites have been used to study Fenton and photo-Fenton reactions, they have not been tested for their prowess in the degradation of the dye Rhodamine-6G (Rh-6G). Nano- and micro-sized iron oxides have been used for its photodegradation [ 16 ]. In the current study, we present a simple yet scalable technique of synthesis of diatom-FeO x composites from live cultures of diatoms and their

The Influence of Detergents on the Bleaching Process, Laser Properties of Rhodamine 6G and B in Aqueous Solution Z. Konefał Institute of Physics, University of Gdansk, 80-952 Gdansk, Poland Z. Naturforsch. 34a, 551 — 556 (1979); received Dezember 5, 1977 The bleaching and the laser properties of Rhodamine 6G and B in aqueous detergent solutions have been studied. The rate of bleaching depends on the concentration of the detergent. The relative quantum yields of the bleaching process for these solutions have been determined. It is found that the influence

contains a selective facet protecting agent. With the help of this basic idea it is possible to achieve quite a few different morphologies like rods [ 19 ], prisms [ 20 ], octahedral [ 21 ] or rhombic dodecahedra [ 22 ]. In this work we will use spherical GNPs as an isotropic structure. In contrast to that rods and prisms will be used as anisotropic structures. For all of the three geometries the behaviour of quenching of the emission of Rhodamine 6G (R6G) dye molecules will be investigated. The knowledge of the quenching mechanism, the rate and a possible facet

peptidomimetic inhibitors, Eur. J. Biochem., 2001, 268, 2669–2677 http://dx.doi.org/10.1046/j.1432-1327.2001.02152.x [29] Maesaki S., Marichal P., Bossche P.V., Sanglard D., Kohno S., Rhodamine 6G efflux for the detection of CDR1-overexpressing azole-resistent Candida albicans strains, J. Antimicrob. Chemother., 1999, 44, 27–31 http://dx.doi.org/10.1093/jac/44.1.27 [30] Gear A.R.L., A potent inhibitor of mitochondrial oxidative phosphorylation, J. Biol. Chem., 1974, 249, 3628–3637 [31] Hope W.W., Drusano G.L., Antifungal pharmacokinetics and pharmacodynamics: bridging from

(isolated in ca. 28 %), after completion. The reported synthetic examples are shown in Figure 4 . Figure 4: Synthetic examples of iodoperfluoroalkylation of alkenes using PDI as a conPET photoredox catalyst. 2.2 Rhodamine 6G (Rh-6G) radical anion Following the seminal work on PDI conPET photoredox catalytic system, the König group reported a second-generation conPET photoredox catalytic system using rhodamine 6G ( Rh-6G ) as a photosensitizer [ 14 ]. Rhodamine 6G, a widely applied fluorescent xanthene dye, generates a stable radical anion upon photoexcitation in the