New chemosensors based on thiomacrocycle-containing coumarin-343 fluoroionophor: X-ray structures and previous results on the effect of cation binding on the photophysical properties

Two new emissive chemosensors based on coumarin-343 have been synthesized, and their photophysical studies conducted. L1 contains an aza-thio macrocycle ring as the chelating unit, which has great affinity for soft metal ions, whereas L2 is a parent species without macrocyclic unit. Both compounds were separated by column chromatography and characterized by elemental analysis, 1H,13C NMR, UV–vis and FAB mass spectroscopy. The X-ray structures of L1 and L2 and the supramolecular interactions in the solid state are discussed. Preliminary results on the metal–ion sensing effects of the ligands are presented. Titrations with Ag+, Pd2+ and Ni2+ have been studied by UV–vis absorption and fluorescence spectroscopy.

Graphical abstractL1, a new emissive dye derived from coumarin-343 bearing an aza-thio macrocycle ring as chelating unit, and its parent compound L2, without the macrocycle ring, have been synthesized in a very good yield. Both compounds show very promising intensity fluorescence quantum yields. Preliminary results concerning the metal–ion sensing effects are presented. Titrations with Ag+, Pd2+, and Ni2+ have been studied by UV–vis absorption and fluorescence spectroscopy.Figure optionsDownload full-size imageDownload as PowerPoint slide