Ratiometry of monomer/excimer emissions of dipyrenyl calix[4]arene in aqueous media

Cation-induced fluorescent excimer emission in calix[4]arene-chemosensors bearing quinoline as a fluorogenic unit: experimental, molecular modeling and crystallographic studies

“…17). 5,[15][16][17][18][19][20][21]53 However, it was surprising that ionophores 1-3 do not show any excimer emission.…”

“…5,[12][13][14][15][16][17][18][19][20] Highly p-delocalized planar systems such as pyrene generally show greater tendency to form excimer and recently it has been extensively used with calixarene to design excimer-based fluoroionophores. 5,[15][16][17][18][19][20][21][22] Most of the systems of this class of compounds contain pyrene as a fluorogenic unit and the latter forms an intramolecular excimer due to strong p-p interaction between two pyrene units and this excimer emission is perturbed in the presence of guest ions. It has been reported that the excimer emission is strongly quenched upon addition of Pb 2+ and Fe 3+15,17-22 whereas significant enhancement of excimer emission intensity is reported for metal ions such as In 3+ , K + and Li + and anions like F À .…”

Coumarin-Based Dual Chemosensor for Colorimetric and Fluorescent Detection of Cu2+in Water Media

“…Meanwhile, a fluorescence-based analytical method can also determine Cu 2+ ions at ppb levels, which is simpler and less expensive than the above methods. , Furthermore, a fluorescence-based analytical method can be used to monitor substances in living cells to detect abnormal cases and causes of diseases. − Therefore, the development of new fluorescent probes for Cu 2+ ions has attracted special attention of scientists. − So far, many fluorescent probes for Cu 2+ ions have been reported. The development of new fluorescent probes is, however, still being concerned due to the limitations of reported probes such as low sensitivity and selectivity, , a narrow range of pH, ,− working in solutions with a high proportion of organic solvents, , and excitation wavelength in the ultraviolet region. ,,, These limitations reduce the application of probes to monitor Cu 2+ ions in living cells.…”

A new fluorescent chemosensor for Hg2+ in aqueous solution

“…Accordingly, developing new and practical sensing systems for Hg 2+ ions remains a challenge. As a part of our continuing interest in the design of fluorescent chemosensors for HTM ions , we developed a dimethylaminocinnamaldehyde‐aminothiourea derived Schiff base (DA) for the selective detection of Hg 2+ ions in aqueous solution (Scheme ).…”