New Group 13 MIL-53 Derivates based on 2,5-Thiophenedicarboxylic Acid

A new rigid metal-organic framework (MOF) with MIL-53 topology built of 2,5-thiophenedicarboxylate (TDC) and Al, Ga, or In is reported. Its structure contains chains of trans corner sharing MO6 octahedra, connected by the linker molecules to form microporous square shaped 1D channels. A combination of powder X-ray diffraction (PXRD), density functional theory (DFT) calculations, and H-1, C-13, and Al-27 solid-state NMR spectroscopy (ssNMR) was used to analyse the structures in detail. The synthesis is easily scaled-up using microwave assisted solvothermal conditions. All materials possess a high thermal stability up to 420 degrees C in air and permanent porosity towards N-2, H-2, CO2, and CH4. Al-MIL-53-TDC shows a high specific surface area of as, BET = 1150 m(2).g(-1) with a micropore volume of V-mic = 0.48 cm(3).g(-1) as well as water uptake of 5.5H(2)O molecules per sum formula (469 mg.g(-1)) with an a sigmoidal shape, advantageous for heat-transformation processes. Noteworthy, this material adsorbs 2.1 wt% H-2 at -196 degrees C and 1 bar, which surpasses other Al-MIL-53 compounds based on linear functionalized terephthalates.