Chromone@Cucurbit[7]Uril Triggers The Luminescence Of Lanthanides In Water

Chromone (CMO) and cucurbit[7]uril (Q[7]) interact with each other in aqueous solution to form a 1 : 1 inclusion complex CMO@Q[7] (L). The inclusion complex coordinates with Eu3+, Tb3+, Dy3+, and Sm3+ ions to form four complexes: L@Eu3+, L@Tb3+, L@Dy3+, and L@Sm3+. The complexation of these four lanthanide ions induces fluorescence emission corresponding to their respective characteristic spectral lines. Detailed luminescence studies have shown that the ternary rare-earth complexes exhibit strong fluorescence intensities and long lifetimes. The formation of these complexes with L not only triggers luminescence of lanthanides, but also produces specific fluorescence responses to antibiotics in aqueous solution, successfully demonstrating a new type of application for this supramolecular system.