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Perylene solid solutions

For solid solutes, the melting point contributes only to the intercept of the solubilization profile. The independence of the intrinsic solubility and the solubilization slope can be demonstrated by the isomers benzo(a)pyrene and perylene. Fig. 5A shows the solubilization of benzo(fl)pyrene and perylene in ethanol/ water systems. The logf o/w s (or aqueous activity coefficients) can be considered to be equal for these two compounds, however, their melting points are different. Benzo(a)pyrene has a melting point of 179°C, while perylene has a melting point of 273°C, and as a result, the latter has a lower intrinsic solubility. Yet both compounds have solubilization slopes (cr) which are nearly identical. This is because cr is soley a function of the activity coefficients (log o/w)-... [Pg.3319]

Correlation of the Solubility of Solids in Various SCF. The new LC mixing rules were also tested for the solubility of a large number of solid solutes in various SCFs. The critical temperatures and pressures of solids and SCFs were taken from refs 24 and 25. The molar volumes of the solids and their saturated vapor pressures were taken from ref 25. The saturated vapor pressure of perylene was found in ref 26. The results are compared with the van der Waals mixing rules in Table 2, which shows that they are comparable. The parameters of SRK EOS (a and b) can be expressed by combining one of eqs 17a—c with one of eqs 18a—c. Only a few combinations have been included in Table 2 the other ones have also been tested and provided comparable results. [Pg.148]

Mixed Crystals and Solid Solutions of Perylene Diimide Pigments... [Pg.256]

These are undoubtedly the most widely studied compounds of perylene with simple anions, mainly AsFg and PFg and their solid solutions, and for some stoichiometries the most conductive at room temperature. Besides the several stoichiometries they present, as in the perchlorate salts [3,36], an additional problem comes from the incorporation of solvent in the crystal structure. In the following we will divide into sections the discussion of the different aspects of the chemistry and physics of these compounds and their solid solutions. [Pg.96]

Attaching perylene moieties as side groups allows achievement of high concentration without affecting the electronic structure of the polymer backbone. Putting 16% perylene moieties as side chains predictably results in more efficient energy transfer, observed with polymer 360, both in solution and solid state (emission band at 599 nm). Although no PLED device with 360 has been reported, this material showed excellent performance in solar cells (external photovoltaic QE = 7%, in blend with PPV) [434]. [Pg.177]

Knowledge of how aluminum chloride oxidizes aromatics to cation radicals is practically non-existent. At one time it seemed that a nitro compound was a necessary co-acceptor (Buck et al., 1960) and that, whereas with mononuclear alkylaromatics, the Lewis acid-nitro compound pair formed only charge transfer complexes (Brown and Grayson, 1953), complete electron transfer occurred with more easily oxidized aromatics. But, cation-radical formation from perylene, anthracene, and chrysene was found to occur in carbon disulfide, chloroform, and benzene solutions, too (Rooney and Pink, 1961) and even occurs on warming anthracene and naphthacene with solid aluminum chloride (Sato and Aoyama, 1973). There is no doubt that a nitro compound enhances electron transfer, however (Sullivan and Norman, 1972). Cation radical formation in AlCl3-nitromethane has been estimated as approximately 100% as compared with 1% in sulfuric acid oxidation of dialkoxybenzenes (Forbes and Sullivan, 1966). Unfortunately, aluminum halide salts have not been isolated and, therefore, even the beginnings of analytical data have yet to be collected. There is no definite knowledge of either the nature of the counter ion or the fate of the electrons in these cation-radical formations. [Pg.166]

Cation radicals may be oxidized further, and some of them become stable dications. This process is often characterized as the second wave in two successive anodic one-electron oxidations. The thianthrene dication is now well known (Shine and Piette, 1962 Hammerich and Parker, 1973), but has not been isolated. On the other hand, the dipcrchloratc of 2,3,7,8-tetramethoxythianthrene dication is a blue solid (Glass el al., 1973). Dications of some aromatics which are well-known for forming stable cation radicals (e.g. perylene) have been made in FS03H-SbF5 solution (Brouwer and van Doom, 1972). Irradiation of hexachlorobenzcne cation radical in SbFs-Cl2 causes the formation of the dication (in this case, a triplet state) (Wasserman et al., 1974). Oxidation of metallo-porphyrin cation radicals to stable (but reactive) dications is quite common (Dolphin et al., 1973). [Pg.219]

Due to the low mole ratio of dye units present, the above copolymers, with perylene dyes in the main chain or as end groups, show energy transfer only in the solid state. If the dyes are attached on the side chain, then copolymers containing much higher mole ratios of chromophore are accessible. The copolymer 123 (Scheme 57) in which 33% of the fluorene units have dyes attached (m n = 2 1) showed energy transfer in solution as well as in a thin film [224]. The emission colour differed slightly between the two states, with the emission maximum appearing at A,max = 561 nm in solution with a shoulder at 599 nm, and at Xmax = 599 nm in the solid state. This is probably due to interaction of the chromophores in the solid phase. [Pg.43]

Amino anthraquinone compounds spectra of solutions and of solid-state samples Asphaltic materials ultraviolet spectra Polynuclear aromatic compounds in high-boiling petroleum fractions spectrophotometric identification included anthracene, pyrene, perylene... [Pg.328]

In contrast to the solution absorption spectra of N, -dialkyl diimide perylenes, which are independent of the V-alkyl group, the shapes of their solid state absorption bands are very sensitive to the structure of the V-alkyl group [236,237]. The appearances of thin films of N,I ... [Pg.521]

Lamotte et al. have examined the reactivity of upper electronically excited states of pyrene and perylene in liquid and solid alkane solutions. °At low temperatures, irradiation of pyrene at 185 or 248 nm in both methane and cyclohexane matrices leads to four detected photoproducts, including high yields of 1-substituted pyrenyl derivatives. Several substituted perylenes were obtained upon 185 or 248 nm irradiation in liquid and solid alkane solutions. A mechanism for alkylation of the aromatic solutes involving sequential absorption of two photons at 248 nm or one photon at 185 nm has been proposed. [Pg.82]


See other pages where Perylene solid solutions is mentioned: [Pg.3225]    [Pg.256]    [Pg.268]    [Pg.100]    [Pg.63]    [Pg.175]    [Pg.188]    [Pg.213]    [Pg.67]    [Pg.350]    [Pg.48]    [Pg.624]    [Pg.244]    [Pg.13]    [Pg.350]    [Pg.22]    [Pg.219]    [Pg.325]    [Pg.168]    [Pg.245]    [Pg.32]    [Pg.195]    [Pg.1519]    [Pg.2766]    [Pg.94]    [Pg.413]    [Pg.116]    [Pg.256]    [Pg.119]    [Pg.269]    [Pg.122]    [Pg.94]    [Pg.138]    [Pg.520]    [Pg.152]   
See also in sourсe #XX -- [ Pg.268 ]




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