Cation-coordinating properties of perfluoro-15-crown-5

Abstract

The coordinative properties of perfluoro-15-crown-5 with monocations were investigated using 19F NMR spectroscopy and ion-selective electrodes with perfluoro-15-crown-5 as the matrix of their sensor membranes and the fluorophilic tetrakis[3,5-bis(perfluorohexyl)phenyl]borate as ion exchanger site. The results show that perfluoro-15-crown-5 interacts weakly but significantly with Na+ and K+. Assuming 1:1 stoichiometry, the formal complexation constants were determined to be 5.5 and 1.7 M−1, respectively. This weak binding is consistent with the strong electron withdrawing nature of the many fluorine atoms in the perfluorocrown ether. While perfluorinated crown ethers have been known to form host–guest complexes with the anions O2− and F− in the gas phase, this is the first study that quantitatively confirms cation binding to a perfluorocrown ether.

Multicore Liquid Perfluorocarbon‐Loaded Multimodal Nanoparticles for Stable Ultrasound and 19F MRI Applied to In Vivo Cell Tracking

“…Thus, our results indicate that not only hydrophobic interactions but also other effects could play a role in the formation of multicore structure. Though it appears surprising that PFCE is close to water in the nanoparticles, it is known that PFCE can form complexes with some anions in the gas phase and also weak complexes with cations . The strong electron‐withdrawing nature of fluorine could possibly be the reason for the occurrence of HOE effect.…”

Ion-Selective Electrodes with Unusual Response Functions: Simultaneous Formation of Ionophore–Primary Ion Complexes with Different Stoichiometries

“…This method 29,53,54 was already used in the past to determine complex stabilities in fluorous membranes. 43,45,48 For the purpose of this work, tetraphenylphosphonium (PPh 4 + ) was chosen as the ion that does not form complexes with the ionophore.…”

Paramagnetic fluorinated nanoemulsions for sensitive cellular fluorine-19 magnetic resonance imaging

“…The metal must not efflux from the fluorous phase during cell labelling and after in vivo administration. The high electronegativity of fluorine imparts very low cohesive energy density 13 and Lewis basicity 14 to heavily fluorinated compounds, making them extremely poor solvents and ligands. The choice of ligands compatible with fluorous phase is therefore limited to the most hydrophobic scaffolds, with as few intermolecular interactions as possible.…”