Assembly, stabilities, and photophysical behaviors of highly efficient luminescent materials fabricated from a terbium complex doped silica/polymer hybrids

Abstract

A series of hybrid polymeric materials Tb-L xerogel, Polymer-Tb-L xerogels (polymer=PVB, PVP, or PMMA) fabricated from a new highly luminescent Tb(III) complex TbL2(NO3)3 (Φ=42.65%) of β-diketone ligand [L=N-(6-(2-methylpyridinyl))trifluoroketoacetamide] were successfully assembled by sol–gel process. The Fourier transform infrared spectra, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetry (TG), UV–visible spectra and photophysical behaviors of Tb(III) complex and Tb(III) complex doped hybrids (Tb-L xerogel, Polymer-Tb-L xerogels) are investigated in detail. The hybrids display more efficient unit mass luminescence emission, enhanced thermal stability, and improved exposure durability in comparison with the pure complex, due to the steric restriction effect from the rigid SiO and SiC polymeric network. In addition, the hybrids Polymer-Tb-L xerogels represent longer lifetime and higher quantum efficiency than that of the hybrid Tb-L xerogel. The result may support the conclusion that the polymers could not only enwrap the lanthanide complexes to keep the donors and acceptors close, but also transfer energy to the central Tb(III) ions. Comparatively, PVP-Tb-L xerogel represents the longest lifetime (1047.07μs) and highest quantum yield (34.09%). At the same time, concentration effects on the luminescence intensity were investigated. The luminescence intensity decreases, however, with increasing complex concentration in the Polymer-Tb-L xerogels. The research of this work attempted to assemble the highly efficient luminescent materials containing the optimal combination of lanthanide complex and matrices.