Fluorescent hydroxyflavone-zeolite nanoparticles: ship-in-a-bottle synthesis and photophysical properties

3-Hydroxyflavone (3-OHF) was incorporated in zeolite micropores by ship-in-a-bottle synthesis. This strategy consists of constructing the molecule by reaction of small precursors within the cavity. 3-OHF molecules exhibit excited-state intramolecular proton transfer (ESIPT) and a tautomeric equilibrium between the 3-OHF-excited structures N* and T*exists. This equilibrium is strongly affected by the protic nature and polarity of the surrounding medium. The textural and spectroscopic characterization of the dye-loaded zeolite colloids enabled the study of the correlation between the optical properties of the dye and the zeolite micropore environment.