RESUMO
The first near IR fluorescent probe for the chemoselective and enantioselective recognition of arginine in aqueous solution is reported in this work. This probe, made of a 1,1'-binaphthyl-based chiral aldehyde unit and a rhodamine-based near IR chromophore, in combination with La3+ exhibits highly chemoselective as well as enantioselective fluorescent enhancement with arginine at λ=764â nm upon excitation at λ=690â nm. Little or no fluorescent response is observed toward the chirality miss-matched arginine enantiomer or other common amino acids and their enantiomers. This probe also allows visual discrimination of the arginine enantiomers because of its fast and distinct color change upon interaction with the substrate.
RESUMO
A novel C3 symmetric 1,1'-bi-2-naphthol-based Schiff base (R,R,R)-6 has been synthesized which shows highly selective fluorescence enhancement with Zn2+ among 21 metal cations examined. Its sensitivity and selectivity are found to be greater than other related C2 (1) and C1 [(R)-9] symmetric compounds in the fluorescent recognition of Zn2+ . The mechanistic study reveals that the selective fluorescence enhancement of the probe can be attributed to the formation of a unimolecular multidentate 6-coordinated Zn2+ complex.
RESUMO
A novel fluorinated chiral dialdehyde (S,S)-1, prepared from (S,S)- or (R,R)-2,6-bis(1-hydroxyethyl)pyridine and 2-naphthol containing a highly fluorinated alkyl group, is found to show enantioselective and chemoselective fluorescent recognition of lysine in the fluorous phase. We discovered that the fluorous phase greatly enhances the fluorescent sensitivity and selectivity of the probe. Thus, the fluorous phase not only can allow the fluorescence measurement to be conducted away from common organic and aqueous media to minimize undesirable interference but also can provide a unique environment to greatly improve the selective fluorescent response.