- The quest for highly fluorescent chromophores: Evaluation of 1H,3H-isochromeno[6,5,4-mna]xanthene-1,3-dione (CXD)
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Photophysical properties of the strongly fluorescent dye, 1H,3H-isochromeno[6,5,4-mna]xanthene-1,3-dione (CXD), are reported. This highly planar, rigid dye absorbs at around 420 nm, which is ideal for excitation with a blue laser diode, and is extremely stable towards prolonged illumination. Under near-UV excitation, the dye readily sensitises free-radical polymerisation, forming a plastic film with excellent optical transparency. Weakly structured emission is observed with a small Stokes' shift and remains essentially insensitive to changes in solvent polarity. For example, in tetrahydrofuran the fluorescence quantum yield is 0.96 while the excited-singlet state lifetime is 7.4 ns. Quantum chemical calculations provide further insight into the electronic nature of the dye in solution.
- Al-Aqar, Roza,Avis, Daniel,Benniston, Andrew C.,Harriman, Anthony
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p. 53072 - 53078
(2015/02/18)
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- Catalytic oxidation of acenaphthene and its derivatives in acetic acid
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The chemistry of formation of products of acenaphthene oxidation in the presence of the catalyst containing both manganese and cobalt bromides under batch conditions is discussed. The main reaction products are acenaphthene quinone, acenaphthenol-9, trans-acenaphthylene glycol, naphthalide, and naphthalic anhydride. The sequence of reactions leading to the final products is established. It is shown that the main oxidation product in the presence of the manganese-based catalyst is naphthalic anhydride, and the main product in the presence of the cobalt-based catalyst is acenaphthene quinone. The process and engineering techniques providing for the high overall and fractional yields of the desired products are discussed.
- Bukharkina, Tatiana V.,Grechishkina, Olga S.,Digurov, Nikolai G.,Kon'kov, Ivan I.
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p. 394 - 400
(2013/09/06)
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- Benzoxanthene-3,4-dicarboximides and Benzimidazoxanthenoisoquinolinones
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Some benzoxanthene-3,4-dicarboximides and benzimidazoxanthenoisoquinolinones are synthesized, and their physical properties and spectral data are determined.
- Xuhong, Qian,Shengwu, Ren
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p. 528 - 529
(2007/10/02)
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