- Water-induced fluorescence quenching of mono- and dicyanoanilines
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Photophysical properties of monocyano- (2-, 3-, and 4-cyano) and dicyano- (3,4-, 3,5-, 2,3-, 2,4-, 2,5-, and 2,6-dicyano) anilines are investigated by fluorescence measurements. All the monocyanoanilines are virtually nonfluorescent in water (quantum yield 0.01); however, in nonaqueous solvents (cyclohexane, acetonitrile and ethanol), the fluorescence quantum yield is enhanced substantially. In contrast, dicyanoanilines investigated are highly fluorescent both in aqueous and nonaqueous environments. The photophysical data and MO calculations suggest that conformational changes in the amino group and variation of hydrogen-bonding interactions between the solute and solvent water upon electronic excitation are responsible for the water quenching in the monocyanoanilines.
- Oshima, Juro,Yoshihara, Toshitada,Tobita, Seiji
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p. 306 - 311
(2008/02/13)
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- 3H-azepines and related systems. Part 5. Photo-induced ring expansions of o-azidobenzonitriles to 3-cyano- and 7-cyano-3H-azepin-2(1H)-ones
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Unlike other aryl azides bearing electron-withdrawing ortho-substituents, o-azidobenzonitriles on photolysis in aqueous-tetrahydrofuran yield mixtures of the expected 3-cyano- and the unexpected 7-cyano-3H-azepin-2(1H)-ones. In one instance ring contraction to a 2-azabicyclo[3.2.0]hept-6-ene-3-one is noted. X-ray crystallographic data for 7-cyano- and 4-chloro-7-cyano-3H-azepin-2-one, and for the azabicycloheptenone, are presented.
- Lamara,Redhouse,Smalley,Thompson
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p. 5515 - 5525
(2007/10/02)
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- Electron-Transfer Substitution Reactions: Facilitation by the Cyano Group
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It is now clear that a cyano group facilitates electron-transfer substitution reactions.Of particular interest is the demonstration that electron-transfer chain substitution at a saturated carbon atom has been achieved in the absence of a nitro group.
- Kornblum, Nathan,Fifolt, Michael J.
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p. 1311 - 1322
(2007/10/02)
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