Macrocycle-Assisted Cooperative Fe3+ Coordination and Fluorescence Regulation in a Coumarin-Functionalized Calix[4]arene
ACS Omega, vol.11, no.18, pp.27493-27503, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 11 Issue: 18
- Publication Date: 2026
- Doi Number: 10.1021/acsomega.6c02160
- Journal Name: ACS Omega
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Directory of Open Access Journals
- Page Numbers: pp.27493-27503
- Kocaeli University Affiliated: Yes
Abstract
A coumarin-functionalized calix[4]arene was designed and synthesized as a supramolecular fluorescent platform for the selective recognition of Fe3+ ions in aqueous media. The preorganized calix[4]arene cavity, combined with the coordinating oxygen- and nitrogen-donor sites of the coumarin unit, enables effective host–guest interactions with Fe3+, resulting in pronounced fluorescence quenching. Spectroscopic investigations revealed that the quenching process proceeds through a combination of static complex formation and dynamic collisional pathways, supported by Stern–Volmer analysis. Job’s plot analysis indicated a 1:2 binding stoichiometry (Fe3+/ligand), highlighting the cooperative role of the calixarene framework in metal-ion coordination. The sensor exhibits a low detection limit of 0.30 μM and a wide linear response range from 33 to 354 μM toward Fe3+, while maintaining a high selectivity in the presence of competing metal ions. The applicability of the supramolecular system was further demonstrated through the determination of Fe3+ ions in real water samples with satisfactory recovery values. This study illustrates how the integration of a coumarin fluorophore into a calix[4]arene scaffold provides an effective coordination-driven fluorescence modulation platform, offering insight into calixarene-based metal-ion recognition systems relevant to supramolecular and coordination chemistry.