Synthesis and fluorescent properties of lanthanide complex covalently bonded to porous silica monoliths

Schiff base synthesized by APTES (3-aminopropyltriethoxysilane) and salicylaldehyde was used as the ligand for coordination with Eu3+ ions. It was covalently attached with meso-structured monoliths via post-synthetic method. The assembly materials were characterized by infrared spectra, CHN elemental analysis, BET analysis and luminescence measurement. The results showed that assembly material had much weaker emission intensity of the ligand, which indicated that energy transfer from ligand to Eu3+ in the assembly became more efficient than that in the neat complex. Additionally, Eu-assembly sample exhibited much longer lifetime and higher emission quantum efficiency of Eu3+ than those of the neat complex.