Fluorescers perylene

Similar results were obtained with the diperoxides 5 (R phenyl) and 5 a (R />-chlorophenyl) and dibenzanthrone or other fluorescers (perylene, rhodamine B, 9.10-diphenylanthracene, anthracene, fluorescein), with quantum yields of the respective chemiluminescence in the range 3.29 X 10 8.... 5.26 X 10 6. 

Scheme 20. Polyphenylene dendrimers in the 1st 68 and in the 2nd generation 70 which are decorated with fluorescent perylene imide chromophores on the surface. Perylenedicarboxi-mide derivative 69 serves as a model compound for spectroscopic investigations.

Moore et al. used a convergent approach to construct first- to sixth-generation dendrons based on arylacetylene units. These were functionalised at the focal point with a - fluorescent - perylene unit and investigated with regard to their flu-... 

In order to visualize the enzyme acting on the substrate, it was labeled with a water-soluble and highly photostable, fluorescent perylene diimide derivate (PDI) [41,42]. When labeled aPLAl ( 10 M) was added to a non-labeled POPC multilayer (stacks of bilayers), enzymes could be visualized as bright spots and areas of high enzyme localization could be clearly seen (Fig. 25.4). 

J. Baggerman, D. C. Jagesar, R. A. L. Vallee, J. Hofkens, F. C. De Schryyer, F. Schelhase, F. Vogtle, A. M. Brouwer, Fluorescent perylene diimide rotaxanes spectroscopic signatures of wheel-chromophore interactions, Chem.-Eur. J., 2001, 13, 1291-1299. 

Stolarski, R., Fiksinski, K.J. Fluorescent perylene dyes for liquid crystal displays. Dye. 

This is supported by energy transfer experiments with added fluorescers (perylene, rubrene, DP A) and by negative evidence for singlet oxygen involvement. 

Instead of dibenzanthrone, other fluorescers (perylene, rhodamine B, fluorescein, DPA, anthracene) can be used. The excitation yields were found [34] to be in the range 7.74 x 1(T to 8.76 x 10 . ... 

Decomposition of diphenoylperoxide [6109-04-2] (40) in the presence of a fluorescer such as perylene in methylene chloride at 24°C produces chemiluminescence matching the fluorescence spectmm of the fluorescer with perylene was reported to be 10 5% (135). The reaction follows pseudo-first-order kinetics with the observed rate constant increasing with fluorescer concentration according to = k [flr]. Thus the fluorescer acts as a catalyst for peroxide decomposition, with catalytic decomposition competing with spontaneous thermal decomposition. An electron-transfer mechanism has been proposed (135). 

Benzo[ghi]perylene (1,12-benzoperylene) [191-24-2] M 276,3, m 273°, 277-278.5°, 278-280°, Purified as light green crystals by recrystn from CfiH6 or xylene and sublimes at 320-340° and 0.05mm [UV Helv Chim Acta 42 2315 7959 Chem Ber 65 846 1932 Fluoresc. Spectrum J Chem Soc 3875 7954]. 1,3,5-Trinitrobenzene complex m 310-313° (deep red crystals from C6Hg) picrate m 267-270° (dark red crystals from CgH6) styphnate (2,4,6-trinitroresorcinol complex) m 234° (wine red crystals from CgH6). It recrystallises from propan-l-ol [J Chem Soc 466 7959]. 

Fluorescent small molecules are used as dopants in either electron- or hole-transporting binders. These emitters are selected for their high photoluminescent quantum efficiency and for the color of their emission. Typical examples include perylene and its derivatives 44], quinacridones [45, penlaphenylcyclopenlcne [46], dicyanomethylene pyrans [47, 48], and rubrene [3(3, 49]. The emissive dopant is chosen to have a lower excited state energy than the host, such that if an exciton forms on a host molecule it will spontaneously transfer to the dopant. Relatively small concentrations of dopant are used, typically in the order of 1%, in order to avoid concentration quenching of their luminescence. 

FIGURE 15.28 Chemiluminescence, the emission of light as the result of a chemical reaction, occurs when hydrogen peroxide is added to a solution of the organic compound perylene. Although hydrogen peroxide itself can fluoresce, in this case the light is emitted by the perylene. 

Reagents. Perylene was obtained from Sigma Chemical Company (St. Louis, Missouri). All other PAHs were supplied by Aldrich Chemical Company (Milwaukee, Wisconsin) and were reported to contain less that 3% impurities. All PAHs were used without further purification. Isopropyl ether (99%) for extraction work was also purchased from Aldrich. Hydroquinone, a fluorescent stabilizer present in the ether, was removed prior to solution preparation by rotary evaporation. Fluorometric-grade 1-butanol was supplied by Fisher Scientific Company (Fair Lawn, New Jersey). All solutions for extractions of PAHs were prepared by evaporating portions of a stock cyclohexane solution and diluting to the appropriate volume with isopropyl ether. Fluorescence measurements were performed on 1 10 dilutions of the stock and final organic phase solutions. The effect of dissolved CDx on the fluorescence intensity of the organic phase PAH was minimized by dilution with isopropyl ether. 

Figure 8.2 Optical transmission images of pe lene (a), anthracene (b), and pyrene (c) microc stalsirradiated bythe NIRIaser scale bar 5 Xm. (d) Emission spectra offluorescence spots in the microcrystals of anthracene (dotted line), pyrene (broken line), and perylene (smooth line), (e) The dependence of the fluorescence...

Emission spectra at these points are shown in Figure 8.2d. The band shapes were independent of the excitation intensity from 0.1 to 2.0 nJ pulse . The spectrum of the anthracene crystal with vibronic structures is ascribed to the fluorescence originating from the free exdton in the crystalline phase [1, 2], while the broad emission spectra of the pyrene microcrystal centered at 470 nm and that of the perylene microcrystal centered at 605 nm are, respectively, ascribed to the self-trapped exciton in the crystalline phase of pyrene and that of the a-type perylene crystal. These spectra clearly show that the femtosecond NIR pulse can produce excited singlet states in these microcrystals. 

Figure 8.2e shows the dependence of the fluorescence intensity on the excitation power of the NIR light for the microcrystals measured with a 20x objective. In this plot, both axes are given in logarithmic scales. The slope of the dependence for the perylene crystal is 2.8, indicating that three-photon absorption is responsible for the florescence. On the other hand, slopes for the perylene and anthracene crystals are 3.9 for anthracene and 4.3 for pyrene, respectively. In these cases, four-photon absorption resulted in the formation of emissive excited states in the crystals. These orders of the multiphoton absorption are consistent with the absorption-band edges for each crystal. The four-photon absorption cross section for the anthracene crystal was estimated to be 4.0 x 10 cm s photons by comparing the four-photon induced fluorescence intensity of the crystal with the two-photon induced fluorescence intensity of the reference system (see ref. [3] for more detailed information). 

Figure 8.3 Interferometric autocorrelation traces of the fluorescence intensities of perylene (a) and anthracene (b) microcrystals irradiated by two NIR Cr F laser pulses centered at 1.26 Xm with the same intensity.

Figure 8.4 (a) Scanning three-photon fluorescence image of pe lene microcrystals obtained by irradiation of the NIR pulse of 1260 nm with power 70 pj pulse scanning step 100nm. (b) Corresponding optical transmission image of the perylene crystals. 

The first observations of P-type delayed fluorescence arose from the photoluminescence of organic vapors.<15) It was reported that phenanthrene, anthracene, perylene, and pyrene vapors all exhibited two-component emission spectra. One of these was found to have a short lifetime characteristic of prompt fluorescence while the other was much longer lived. For phenanthrene it was observed that the ratio of the intensity of the longer lived emission to that of the total emission increased with increasing phenanthrene vapor... 

Kool and co-workers recently reported a multicolor set of water-soluble dyes synthesized through the combination of three to five individual fluorophores assembled on a DNA-like backbone [94, 95]. As a continuation of their previous works on various DNA analogs [96-99], they synthesized the oligodeoxyfluoro-side (ODF) with seven fluorescent monomers, such as pyrene, perylene, dimethy-laminostilbene, and three stilbene derivatives, and they assembled these fluorescent DNA monomers into oligofluor chains using a DNA synthesizer (Fig. 26). Using... 

Chemiluminescence also occurs during electrolysis of mixtures of DPACI2 99 and rubrene or perylene In the case of rubrene the chemiluminescence matches the fluorescence of the latter at the reduction potential of rubrene radical anion formation ( — 1.4 V) at —1.9 V, the reduction potential of DPA radical anion, a mixed emission is observed consisting of rubrene and DPA fluorescence. Similar results were obtained with the dibromide 100 and DPA and/or rubrene. An energy-transfer mechanism from excited DPA to rubrene could not be detected under the reaction conditions (see also 154>). There seems to be no explanation yet as to why, in mixtures of halides like DPACI2 and aromatic hydrocarbons, electrogenerated chemiluminescence always stems from that hydrocarbon which is most easily reduced. A great number of aryl and alkyl halides is reported to exhibit this type of rather efficient chemiluminescence 155>. 

A wide variety of different classes of fluorescent molecules has been investigated in the peroxyoxalate chemiluminescent systems. Among those screened were fluorescent dyes such as rhodamines and fluoresceins, heterocyclic compounds such as benzoxazoles and benzothiazoles, and a number of polycyclic aromatic hydrocarbons such as anthracenes, tetracenes, and perylenes. The polycyclic aromatic hydrocarbons and some of their amino derivatives appear to be the best acceptors as they combine high fluorescence efficiency with high excitation efficiency in the chemiluminescent reaction [28],... 

Optical properties of dendrimers bearing eight chromophores have been examined by single molecule spectroscopy techniques. It is especially exciting that variations in the spectra are recorded if one of these dendrimers is observed for a period of time under continuous irradiation.1481 The fluorescence intensity of the dendrimer nanoparticle also jumps between discrete emissive levels. All these findings suggest the existence of strong electronic interactions between several perylene imide chromophores within one dendrimer and provide new... 

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