Novel luminescent lanthanide(iii) hybrid materials: fluorescence sensing of fluoride ions and N,N-dimethylformamide

Abstract

Two novel luminescent organic–inorganic hybrid materials, Ln(L-SBA15)₃phen (Ln = Eu, Tb), were designed and synthesized. The organic ligand phenylurea was modified by the silane coupling agent 3-(triethoxysilyl)propyl isocyanate (TESPIC) to form a precursor (L), which was covalently bonded onto a mesoporous SBA-15 backbone to form mesoporous L-SBA15 through co-hydrolysis and co-condensation reactions. 1,10-Phenanthroline monohydrate (phen) was selected as the second ligand to improve the luminescence of the final products, and the two mesoporous hybrid materials Ln(L-SBA15)₃phen were obtained after the coordination reaction between the organic ligands (phen and L-SBA15) and Ln(III) ions. Both the mesoporous hybrid materials were examined by Fourier transform infrared spectroscopy, transmission electron microscopy, small-angle X-ray diffraction, N₂ adsorption–desorption curves, and photoluminescence spectroscopy. The results show that both the hybrid materials showed highly ordered mesoporous structures, high surface areas, and excellent photophysical properties (long luminescence lifetimes and high quantum efficiencies). Furthermore, the fluorescence sensing properties of the materials were investigated systematically, and the hybrid materials were revealed to be promising examples of dual functional materials with good ability to sense fluoride ions and a small organic molecule N,N-dimethylformamide.