The syntheses and crystal structures of the monopotassium salts of difluorinated and tri/perfluorinated trimesic acid (1,3,5-benzenetricarboxylic acid ≡ H 3 BTC) are presented, namely, K(H 2 dF-BTC) (Fdd2, Z = 16) and K(H 2 pF-BTC) (Cc, Z = 4). For the first time, together with already known K(H 2 mF-BTC), all fluorination degrees of trimesic acid are accessible and can be used for a systematic study of the influence of fluorination on the stability of the resulting coordination polymers and metal−organic frameworks (MOFs). The monopotassium salts show a decreasing (chemical) stability in water upon heating, as well as a decreasing thermal stability, as evidenced by differential scanning calorimetry/ thermogravimetric analysis (DSC/TGA). A similar decreasing thermal stability is found for two series of isostructural coordination polymers (UHM-33 topology:• 1 / 2 H 2 O with L 2− = HBTC 2-, HmF-BTC 2− and HdF-BTC 2− ). Remarkably, while the decomposition temperatures decrease with increasing fluorination of the linker, the releasing temperatures for embedded solvent molecules (DMA and H 2 O, respectively) increase. To identify possible candidates for the synthesis of isostructural coordination polymers and MOFs with BTC 3− ligands with different degrees of fluorination, a database-adapted approach was developed, which utilizes the increased torsion angle between the carboxylate groups and the phenyl rings in these materials as a structure-determining parameter.

Anhydrous EuII–acetylenedicarboxylate (EuADC; ADC2− = −O2C‐C≡C‐CO2−) was synthesized by reaction of EuBr2 with K2ADC or H2ADC in degassed water under oxygen‐free conditions. EuADC crystallizes in the SrADC type structure (I41/amd, Z=4) forming a 3D coordination polymer with a diamond‐like arrangement of Eu2+ nodes (msw topology including the connecting ADC2− linkers). Deep orange coloured EuADC is stable in air and starts decomposing upon heating in an argon atmosphere only at 440 °C. Measurements of the magnetic susceptibilities (μeff=7.76 μB) and 151Eu Mössbauer spectra (δ=−13.25 mm s−1 at 78 K) confirm the existence of Eu2+ cations. Diffuse reflectance spectra indicate a direct optical band gap of Eg=2.64 eV (470 nm), which is in accordance with the orange colour of the material. Surprisingly, EuADC does not show any photoluminescence under irradiation with UV light of different wavelengths. Similar to SrADC, EuADC exhibits a negative thermal volume expansion below room temperature with a volume expansion coefficient αV=−9.4(12)×10−6 K−1.

Cu‐mediated radiofluorination is a versatile tool for the preparation of 18F‐labeled (hetero)aromatics. In this work, we systematically evaluated a series of complexes and identified several generally applicable mediators for highly efficient radiofluorination of aryl boronic and stannyl substrates. Utilization of these mediators in nBuOH/DMI or DMI significantly improved 18F‐labeling yields despite use of lower precursor amounts. Impressively, application of 2.5 μmol aryl boronic acids was sufficient to achieve 18F‐labeling yields of up to 75 %. The practicality of the novel mediators was demonstrated by efficient production of five PET‐tracers and transfer of the method to an automated radiosynthesis module. In addition, (S)‐3‐[18F]FPhe and 6‐[18F]FDOPA were prepared in activity yields of 23±1 % and 30±3 % using only 2.5 μmol of the corresponding boronic acid or trimethylstannyl precursor.

FMOFs, i.e. metal‐organic frameworks with linkers with fluoro substituents, were supposed to show enhanced thermal and chemical stability as well as high gas affinity and hydrophobicity. However, at least for aromatic carboxylate ligands it was shown in a subsequent work that fluoro substituents weaken the C(phenyl)‐COO– bond and thus facilitate decarboxylation leading to a decreased chemical and thermal stability. Nonetheless, it was concluded that linker fluorination leads to a rich structural chemistry, as the torsion angle between the phenyl ring and the carboxylate group is significantly increased in these compounds. Here, we present the very first examples of four MOFs all based on Sr2+ cations and trimesate‐based linkers with three different degrees of fluorination as well as the known non‐fluorinated counterpart: [Sr(HL)(H2O)]·n H2O [1: L = mF‐BTC3–, n = 0.5, P1, Z = 2; 2: L = dF‐BTC3–, n = 0.5, C2/c, Z = 8; 3: L = pF‐BTC3–, n = 1.5, C2/c, Z = 8; 4: L = BTC3–, n = 0.5, P1, Z = 2; BTC3– ≡ 1,3,5‐benzenetricarboxylate (trimesate); mF‐BTC3– ≡ monofluorinated trimesate, dF‐BTC3– ≡ difluorinated trimesate, pF‐BTC3– ≡ per‐(tri‐)fluorinated trimesate]. Whereas 1 and known 4 are found to crystallize in isotypic structures and 2 in a very similar structural arrangement [all CN(Sr2+) = 9], 3 with the highest degree of fluorination exhibits a completely different crystal structure [CN(Sr2+) = 8], which is already obvious from the different composition. It is shown that the torsion angles between the phenyl ring and the carboxylate groups play an important structure‐directing role. DSC/TGA investigations confirm that with increasing fluorination the thermal stability is decreased. However, the release temperature of water, i.e. the affinity to water, increases with the number of fluoro substituents.

A new MOF (metal‐organic framework), ∞3 [Sc(dF‐BTC)6/6]⋅solvent with dF‐BTC3−=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 (I41/amd, Z=8). In the crystal structure each of the three carboxylate groups of the dF‐BTC3− linker coordinates to two Sc3+ cations, resulting in an almost ideal ScO6 octahedron. The connectivity of these ScO6 and dF‐BTC3− 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 N2 as test gas could be recorded. The small pores within UoC‐4 are obviously not accessible for gases like N2 due to very small opening windows.