Abstract
An [18]crown-6 unit was introduced into a cation-anion dual-ion-sensing quinoxalinone derivative (1) as a new fluorescent molecule for successive cation (K+) and anion (F- and CH3COO-) sensing in CH3CN. High anion-sensing abilities for F- and AcO- were observed at the hydrogen-bonded acidic N-H proton of the positively charged K+-capturing 1 at the [18]crown-6 site due to electrostatic cation-anion interactions. On the other hand, the acidic N-H proton of lactam tautomer 1 strongly recognized basic AcO- or F- anions via N-H⋯AcO- or F- hydrogen-bonding interactions, and further AcO- or F- additions facilitated the deprotonation reaction, forming anionic 1-. Anionic 1- showed a much higher K+-sensing ability at the [18]crown-6 site than neutral 1 through effective cation-anion electrostatic interactions. Interestingly, the electrostatically stabilized zwitterionic K+·1- formed fluorescent organogels in CH3CN, acetone, and THF; the organogels underwent reversible transformation between a blue fluorescent organogel and green fluorescent sol by the addition of trifluoroacetic acid (gel → sol) and trimethylamine (sol → gel). Both K+ and AcO- (or F-) ions acted as the key ions in the fluorescent organogel formation.
Original language | English |
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Pages (from-to) | 6234-6242 |
Number of pages | 9 |
Journal | Journal of Materials Chemistry C |
Volume | 5 |
Issue number | 25 |
DOIs | |
Publication status | Published - 2017 |
ASJC Scopus subject areas
- Chemistry(all)
- Materials Chemistry