Macrocycle-Assisted Cooperative Fe ³⁺ Coordination and Fluorescence Regulation in a Coumarin-Functionalized Calix[4]arene

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.