Photophysical Properties of Lanthanide (Eu3+, Tb3+) Hybrid Soft Gels of Double Functional Linker of Ionic Liquid-Modified Silane

Four kinds of luminescent hybrid soft gels have been assembled by introducing the lanthanide (Eu3+, Tb3+) tetrakis -diketonate into the covalently bonded imidazolium-based silica through electrostatic interactions. Here, the imidazolium-based silica matrices are prepared from imidazolium-derived organotriethoxysilanes by the sol-gel process, in which the imidazolium cations are strongly anchored within the silica matrices while anions can still be exchanged following application for functionalization of lanthanide complexes. The photoluminescence measurements indicated that these hybrid soft gels exhibit characteristic red and green luminescence originating from the corresponding ternary lanthanide ions (Eu3+, Tb3+). Further investigation of photophysical properties reveals that these soft gels have inherited the outstanding luminescent properties from the lanthanide tetrakis -diketonate complexes such as strong luminescence intensities, long lifetimes and high luminescence quantum efficiencies.