- Syntheses and photophysical properties of fluorescent dibenzofurans, a dibenzothiophene, and carbazoles substituted with bensoxazole and hydroxyl groups to produce excited state intramolecular proton-transfer
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Dibenzofurans, a dibenzothiophene, and carbazoles, each substituted with a 2-benzoxazolyl group as well as an ortho-hydroxyl group, were synthesized to produce fluors with fluorescence due to excited-state intramolecular proton-transfer. The orientations for Friedel-Crafts acylation of 3-methoxydibenzothiophene and of the analogous carbazole were determined. The fluors displayed absorption peaks in the 330-385 nm region with molar extinction coefficients up to 57,000. Fluorescence quantum efficiencies of 0.17-0.44 were obtained at wavelengths that had peak values from 540-600 nm. The fluors are of potential use as wavelength shifters in scintillating polystyrene fibers.
- Kauffman,Litak,Boyko
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p. 1541 - 1555
(2007/10/03)
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- Pigment composition
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A pigment composition contains a pigment and a dispersant. The dispersant is a phosphoric ester compound represented by the following general formula: wherein at least one of the three Rs is a residuum of a polyester chain containing as principal bonds thereof ester bonds of a polycarboxylic acid and a polyalcohol.
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- Pigment composition
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A pigment composition contains a pigment and a dispersant. The dispersant is a polyester compound which contains, per molecule, a residuum of at least two benzene rings coupled together, an aromatic ring having at least 8 carbon atoms or a heterocyclic ring having at least 8 carbon atoms, and at least one ester bond as a principal bond.
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