An investigation of the effect of ligands on thermal stability of luminescent samarium complexes

Three kinds of Sm(L)3PhennH2O complexes (L: a-thenoyltrifluoroacetone (HTTA), 4-fluorobenzoicacid (p-FBA) and 4-aminobenzoicacid (p-ABA)) were designed and synthesized by the wet chemical method. Their thermal stabilities were compared through thermogravimetric analysis (TGA) and high temperature photoluminescence measurements. The results indicated that [Sm(p-FBA)3Phen]2 presented the best thermal stability, and the photoluminescence intensity could remain 50% even after being heat-treated at 280 C for 20 min. Not only the rigidity of the organic ligand and complexes structures, but also the coordinating ability between rare earth ions and ligand played a crucial role in the stability of the complexes. In this article, p-fluorobenzoicacid has been proven to be a promising ligand for the preparation of highly luminescent and stable rare earth complexes.