Construction of a series of rare earth metal-organic frameworks supported by thiophenedicarboxylate linker: Synthesis, characterization, crystal structures and near-infrared/visible luminescence

•Six new REMOFs were synthesized and fully characterized.•Photoluminescence properties these coordination networks were investigated.•Energy transfer mechanism for REMOFs has been performed.•An energy level diagram is used to establish the ligand-to-metal energy transfer.•These compounds can act as light conversion molecular devices.

Six novel rare earth metal organic-frameworks with the general formula {[RE2(2,5-tdc)3(dmso)2]·H2O}n (RE = YIII, PrIII, NdIII, SmIII, ErIII and TmIII; 2,5-tdc2− = 2,5-thiophenedicarboxylate anion; dmso = dimethylsulfoxide) were synthesized and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermal analysis (TG/DTA) are reported. Structure analysis reveals that REIII ions show distorted capped trigonal – prismatic geometry. The 2,5-tdc2− ligands connect four REIII centers, adopting (κ1 – κ1) – (κ1 – κ1) – μ4 coordination mode, generating an interesting 3D network with potential application for gas adsorption. Photophysical properties were studied using excitation/emission spectra and the photoluminescence data show the near infrared (NIR) and visible (Vis) emission with the characteristic transitions: 1D2 → 3F2 for PrIII, 4F3/2 → 4IJ (J = 9/2, 11/2 and 13/2) for NdIII, 4G5/2 → 6HJ (J = 5/2, 7/2, 9/2 and 11/2) for SmIII and 4I13/2 → 4I15/2 for ErIII. This study indicates that 2,5-tdc2− ligand is able to act as a sensitizer for emission in NIR and Vis region in these ions.

Graphical abstractNew rare-earth metal-organic frameworks of general formula {[RE2(2,5-tdc)3(dmso)2]·H2O}n (RE = YIII, PrIII, NdIII, SmIII, ErIII, TmIII; 2,5-tdc2− = 2,5-thiophenedicarboxylate anion; dmso = dimethylsulfoxide) were synthesized and their complete characterization, including single crystal X-ray diffraction, FTIR and DR spectroscopy and thermal analysis (TG/DTA) are reported. Photoluminescence data were obtained from the excitation and emission spectra. The energy transfer process in these complexes were studied.Figure optionsDownload full-size imageDownload as PowerPoint slide