Sulfide functionalized lanthanide (Eu/Tb) periodic mesoporous organosilicas (PMOs) hybrids with covalent bond: Physical characterization and photoluminescence

Novel organic-inorganic periodic mesoporous organosilicas (PMOs) were synthesized by linking lanthanide (Tb3+, Eu3+) complexes to the framework of mesoporous through the modified 4-mercaptobenzoic acid (MCBA-Si) using co-condensation method in the presence of Pluronic P123 surfactant as a template. 4-mercaptobenzoic acid (MCBA) grafted to the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TEPIC) was used as the precursor for the preparation of periodic mesoporous materials. The two kinds of resulting materials (denoted as Ln-MCBA-PMOs, Ln = Tb, Eu) were characterized in detail by fourier-transform infrared spectra, ultraviolet-visible diffuse reflection absorption spectra, Si-29 MAS NMR spectra, small-angle X-ray diffraction, nitrogen adsorption/desorption isotherms, photoluminescence spectroscopy and luminescence decay time measurements. The results reveal that luminescent periodic mesoporous materials have high surface area, uniformity in the mesopore structure and good crystallinity. Furthermore, the mesoporous material covalently bonded Tb3+ complex (Tb-MCBA-PMOs) exhibits the stronger characteristic emission of Tb3+ and longer lifetime than Eu-MCBA-PMOs due to the triplet state energy of organic ligand MCBA-Si matches with the emissive energy level of Tb3+ very well. (C) 2010 Elsevier Inc. All rights reserved.