Photoluminescent 3D Lanthanide−Organic Frameworks with 2,5-Pyridinedicarboxylic and 1,4-Phenylenediacetic Acids

Novel three-dimensional lanthanide−organic frameworks with 2,5-pyridinedicarboxylic (2,5-H2pdc) and 1,4-phenylenediacetic acids (1,4-H2pda) were synthesized by hydrothermal synthesis, and characterized structurally using single-crystal and powder X-ray diffraction, elemental and thermogravimetric analyses, FT-IR and photoluminescence spectroscopies, and diffuse reflectance. The structural details of [Ln2(2,5-pdc)2(1,4-pda)(H2O)2] [where Ln3+ = Eu3+, Tb3+, (Eu0.2Tb0.8)3+ and (Eu0.1Tb0.9)3+] and the dehydrated [Eu2(2,5-pdc)2(1,4-pda)] phase were unveiled by single-crystal X-ray diffraction. Photoluminescence measurements performed for the Eu3+ and Tb3+ compounds show emission at room temperature. Energy transfer from Tb3+ to Eu3+ has been observed for the Eu3+/Tb3+ mixed materials.