Enhanced fluorescence and ion adsorption/sensing properties of europium(III) complex with porous structure

An Eu(phen)(2)(NO3)(3) complex was synthesized from a single 1,10-phenanthroline (phen) ligand; the complex possessed a special porous structure, which increased its specific surface area and resulted in a stronger ultraviolet absorption. Flexible light-emitting fibers prepared from the complex via electrospinning exhibited improved photophysical properties, and the quantum yield calculated via the Judd-Ofelt (J-O) theory was up to 55.4%. Moreover, the fluorescence lifetime of the fibers was longer than that of Eu(phen)(2)(NO3)(3). Under irradiation with 340 nm UV light, stronger fluorescence quenching was observed with increasing Fe3+ concentration, highlighting the Fe3+ adsorption capabilities of the present system. Fluorescence measurements showed that the complex had high sensitivity for Fe3+ in aqueous solution. The fluorescence characteristics and porous structure of the complex not only meet the requirements of precursors for flexible high-luminescence fibers, but also have promising application potential for ion adsorption and sensing in aqueous solution.