UoC‐4: A MOF Based on Octahedral ScO 6 Nodes and Fluorinated Trimesate Ligands

A new MOF (metal‐organic framework),∞ 3 [Sc( dF ‐BTC) 6/6 ]⋅solvent with dF ‐BTC 3− =2,4‐difluoro‐1,3,5‐benzene‐tricarboxylate, termed UoC‐4 (UoC≡University of Cologne), was synthesized by solvothermal reaction in an ethanol/water solvent mixture. The crystal structure of UoC‐4 was solved and refined from X‐ray single crystal data ( I 4 1 / amd , Z =8). In the crystal structure each of the three carboxylate groups of the dF ‐BTC 3− linker coordinates to two Sc 3+ cations, resulting in an almost ideal ScO 6 octahedron. The connectivity of these ScO 6 and dF ‐BTC 3− building units leads to a 3D framework structure with a new unprecedented topology. Small voids with a diameter of <5 Å are formed, in which most likely disordered ethanol molecules reside. UoC‐4 is stable against moisture, but in water a slow hydrolysis occurs. Thermal decomposition in an inert atmosphere starts above 400 °C. Activation of the material failed so that no gas sorption isotherm with N 2 as test gas could be recorded. The small pores within UoC‐4 are obviously not accessible for gases like N 2 due to very small opening windows.