Terbium(III) and dysprosium(III) 8-connected 3D networks containing 2,5-thiophenedicarboxylate anion: Crystal structures and photoluminescence studies

Two novel coordination polymers with the formula {[Ln2(2,5-tdc)3(dmso)2]·H2O}n (Ln = Tb(III) for (1) and Dy(III) for (2)), (2,5-tdc2− = 2,5-thiophenedicarboxylate and dmso = dimethylsulfoxide) have been synthesized by the diffusion method and characterized by thermal analysis, vibrational spectroscopy and single crystal X-ray diffraction analysis. Structure analysis reveals that 2,5-tdc2− play a versatile role toward different lanthanide ions to form three-dimensional metal-organic frameworks (MOFs) in which the lanthanides ions are heptacoordinated. Photophysical properties were studied using excitation and emission spectra, where the photoluminescence data show the high emission intensity of the characteristic transitions 5D4 → 7FJ (J = 6, 5, 4 and 3) for (1) and 4F9/2 → 6HJ (J = 15/2, 13/2 and 11/2) for (2), indicating that 2,5-tdc2− is a good sensitizer.

Two novel coordination polymers with the formula {[Ln2(2,5-tdc)3(dmso)2]·H2O}n (Ln = Tb(III) for (1) and Dy(III) for (2)), (2,5-tdc2− = 2,5-thiophenedicarboxylate and dmso = dimethylsulfoxide) have been synthesized by the diffusion method. Structure analysis reveals that three-dimensional metal-organic frameworks (MOFs) were obtained. Photophysical properties were studied using excitation and emission spectra and indicate that 2,5-tdc2− is a good sensitizer.Figure optionsDownload as PowerPoint slideHighlights
► Reaction between 2,5-tdc ligand and Tb(III) or Dy(III) leads to MOFs.
► Both MOFs are 3D nets with rhombic channels formed by Ln2(COO)6 SBUs.
► Luminescence studies show that these MOFs could be useful as fluorescent materials.