Lanthanide-Functionalized SBA-15 Mesoporous Hybrids – Ultraviolet-Visible Excitation and Visible–NIR Emission

Graphical Ln 3+ (Eu 3+ , Nd 3+ , Yb 3+ ) organic–inorganic mesoporous hybrid materials are prepared. The hybrids contain lanthanide complexes covalently grafted to 2-methyl-9-hydroxyphenalenone (MHPO) functionalized ordered mesoporous SBA-15 and with 1,10-phenanthroline as a second ligand. The materials exhibit the characteristic visible (Eu 3+ ) and near-infrared (NIR) luminescence (Nd + and Yb 3+ ) of lanthanides. 9-Hydroxy-2-methyl-phenalenone (MHPO) was synthesized and modified with 3-(triethoxysilyl)propyl isocyanate (TEPIC) through a hydrogen atom addition reaction to achieve a new chemical linkage (named as MHPOSi). SBA-15 mesoporous silica organically functionalized with MHPOSi was synthesized. The MHPOSi was linked to tetraethoxysilane (TEOS) through a condensation process in the presence of Pluronic P123 surfactant as a template. New Ln 3+ (Eu 3+ , Nd 3+ , Yb 3+ ) organic–inorganic mesoporous hybrid materials were prepared, in which the Ln 3+ complexes are covalently attached to SBA-15 and have 1,10-phenanthroline (phen) as a second ligand. The resultant mesoporous hybrids were characterized by FTIR spectroscopy, small-angle X-ray diffraction, N 2 adsorption–desorption measurements, thermal analysis, and UV/Vis spectroscopy. They all have high surface areas, uniform mesostructures, and good crystallinity. The photophysical properties of the functionalized mesoporous SBA-15 networks are discussed in detail and they still present excitation capability in the visible region despite the modification of the organic silane. Subsequently, they exhibit characteristic visible (Eu 3+ ) and near-infrared (NIR) luminescence (Nd + and Yb 3+ ).