- N-(di)icosyl-substituted benzo[a]phenoxazinium chlorides: Synthesis and evaluation as near-infrared membrane probes
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Five benzo[a]phenoxazinium chlorides containing alkyl chains with twenty carbon atoms at the 5- or 9-positions of the tetracyclic ring were efficiently synthesised and characterised by UV/Vis and NIR spectroscopy. The absorption and emission maxima in ethanol occur in the range 627-641 nm and 645-676 nm, respectively, with quantum yields varying from 0.14 to 0.38. Preliminary photophysical studies with these fluorochromophores in zwitterionic [2,3-bis(palmitoyloxy)propyl-2-(trimethylammonio)ethyl phosphate, DPPC] and cationic (N,N-dimethyl-N-octadecyloctadecan-1-aminium bromide, DODAB) vesicles were carried out. The results showed that the new benzo[a]phenoxazinium derivatives are able to detect the gel to liquid-crystalline lipid phase transition through variations in either the extent of H-aggregation or in the acid-base equilibrium. Novel benzo[a]phenoxazinium chlorides possessing icosyl groups as substituents at the 5- or 9-positions of the tetracyclic ring were photophysically studied in both zwitterionic and cationic vesicles. The results revealed that these fluorochromophores are able to detect the gel to liquid-crystalline lipid phase transition through variations either in the extent of H-aggregation or in an acid-base equilibrium. Copyright
- Naik, Sarala,Alves, Carla M. A.,Coutinho, Paulo J. G.,Goncalves, M. Sameiro T.
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p. 2491 - 2497
(2011/06/10)
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- New long alkyl side-chain benzo[a]phenoxazines as micellisation probes
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Several novel fluorescent benzo[a]phenoxazinium chlorides possessing a long aliphatic chain substituent at the 5-amino function of the heterocycle were efficiently synthesised. All compounds obtained absorbed and emitted at longer wavelengths with moderat
- Alves, Carla M.A.,Naik, Sarala,Coutinho, Paulo J.G.,Gon?alves, M. Sameiro T.
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p. 4470 - 4474
(2009/12/03)
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- LONG WAVELENGTH THIOL-REACTIVE FLUOROPHORES
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Reactive fluorescent dyes compositions and methods of using same are disclosed. Squaraine nucleus, Nile red nucleus, benzodioxazole nucleus, coumarin nucleus or aza coumarin nucleus dyes are disclosed dyes are disclosed having thiol-reactive groups. Squaraine nucleus, Nile Red nucleus, benzodioxazole nucleus, coumarin nucleus or aza coumarin nucleus dyes are disclosed that exhibit a fluorescence emission of at least about 575 nm. Biosensors are disclosed having a binding protein and a squaraine nucleus, Nile Red nucleus, benzodiaxazole nucleus, coumarin nucleus or aza coumarin nucleus.
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Page/Page column 21; 44
(2008/06/13)
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- Synthesis and fluorescence properties of side-chain carboxylated 5,9-diaminobenzo[a]phenoxazinium salts
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The efficient synthesis of a series of novel side-chain carboxylated 5,9-diaminobenzo[a]phenoxazinium salts is described. The ring system was prepared by the reaction of 5-alkylamino-2-nitrosophenol hydrochlorides with the appropriate N-alkylated-naphthylamine. Evaluation of the visible and fluorescence properties of the cationic dyes was carried out in ethanol and water at physiological pH. In both solvents they showed intense visible absorption maxima in the range 500-638 nm (ethanol) and 625-650 (water), and fluoresced strongly, with fluorescence maxima from 612 to 669 nm (ethanol) and from 654 to 685 nm (water). A wide variation in fluorescence quantum yields is observed, ranging from 0.051 to 0.50 and 0.065 to 0.32 in ethanol and water, respectively.
- Frade, Vania H. J.,Gon?alves, M. Sameiro T.,Moura, Jo?o C. V. P.
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p. 4949 - 4952
(2007/10/03)
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