Details

Autor(en) / Beteiligte

• Gomes, Liliana J
• Outis, Mani
• Gomes, Clara S B
• Tomé, Augusto C
• Moro, Artur J

Titel

Development of Fluorescent Chemosensors for Calcium and Lead Detection

Ist Teil von

• Molecules (Basel, Switzerland), 2024-01, Vol.29 (2), p.527

Ort / Verlag

Switzerland: MDPI AG

Erscheinungsjahr

2024

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• In the present work, several coumarin-3-carboxamides with different azacrown ether moieties were designed and tested as potential luminescent sensors for metal ions. The derivative containing a 1-aza-15-crown-5 as a metal chelating group was found to yield the strongest response for Ca and Pb , exhibiting an eight- and nine-fold emission increase, respectively, while other cations induced no changes in the optical properties of the chemosensor molecule. Job's plots revealed a 1:1 binding stoichiometry, with association constants of 4.8 × 10 and 8.7 × 10 M , and limits of detection of 1.21 and 8.04 µM, for Ca and Pb , respectively. Computational studies suggest the existence of a PET quenching mechanism, which is inhibited after complexation with each of these two metals. Proton NMR experiments and X-ray crystallography suggest a contribution from the carbonyl groups in the coumarin-3-carboxamide fluorophore in the coordination sphere of the metal ion.