Co-assembly and luminescence tuning of hybrids with task-specified ionic liquid encapsulating and linking lanthanide-polyoxometalates and complexes

Abstract

A class of novel multifunctional hybrids assembled by lanthanide polyoxometalates, ionic liquid and lanthanide complexes were prepared through the reactions of ion exchange and coordination in mild conditions. These hybrids possess two luminescence centers, one is lanthanide polyoxometalates ([EuW₁₀O₃₆]⁹⁻ or [TbW₁₀O₃₆]⁹⁻), the other is lanthanide complexes of 1,10-phenanthroline (phen) (or 2,2′-bipyridine (bpy)) and ionic liquid (1-methyl-3-propionic imidazole unit). Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) analysis, thermo-gravimetric analysis (TGA), UV/vis diffuse reflectance spectra and photoluminescent properties are utilized to characterize these hybrid materials. The results reveal that all hybrids possess amorphous microstructures and are composed of inorganic polyoxometalates and lanthanide nitrate through chemical bonds. Most hybrids exhibit outstanding luminescent properties such as high quantum efficiency and long lifetimes. Moreover, the luminescent color of them can be tuned and even the white luminescence can be integrated.