2026/02/01 by Hefeng Yuan, Bo Yang, Li Cui +2 · 1 voice
Agricultural and Biological Sciences · Chemistry · Medicine · #Boron Compounds in Chemistry #Molecular Sensors and Ion Detection #Plant Micronutrient Interactions and Effects
paper · doi:10.1016/j.gce.2026.02.004
openalex publication_date 2026/02/01 · openalex created_date 2026/02/24 · openalex updated_date 2026/07/22
The selective capture of alkali metal ions in complex systems has consistently been an important but challenging subject in the field of separation science. In this work, three crown ether functionalized ionic liquids (CE-FILs), namely 1-capryl benzo-12-crown-4 ether 3-methylimidazole bis(trifluoromethanesulfonyl)imide ([C 8 (B12C4)mim][NTf 2 ]), 1-capryl benzo-15-crown-5 ether 3-methylimidazole bis(trifluoromethanesulfonyl)imide ([C 8 (B15C5)mim][NTf 2 ]) and 1-capryl benzo-18-crown-6 ether 3-methylimidazole bis(trifluoromethanesulfonyl)imide ([C 8 (B18C6)mim][NTf 2 ]) have been obtained for selective capture of alkali metal ions. Their structures and interactions with alkali metal ions have been investigated. The results reveal that [C 8 (B12C4)mim][NTf 2 ] exhibits the highest selectivity for Na + with a high Na + /Li + selectivity of 391.8. In contrast, both [C 8 (B15C5)mim][NTf 2 ] and [C 8 (B18C6)mim][NTf 2 ] demonstrate the most favorable binding affinity for K + over other alkali metal ions. It is noteworthy that [C 8 (B18C6)mim][NTf 2 ] also shows remarkable selectivity for Rb + and Cs + over Na + and Li + . The chelation-driven process between CE-FILs and alkali metals is governed by host-guest compatibility, ionic hydration energy, and interfacial behavior. The spectroscopic characterization and DFT calculation all support that the interaction of the three CE-FILs with alkali metals involves ion-dipole interaction, hydrogen bonding, and electrostatic interaction. • CE-FILs achieve exceptional selectivity for alkali metal ions. • The complexation structures of CE-FILs are [CE-FIL]...[M] + [FeCl 4 ] – . • The complexation ability is determined by host-guest compatibility, ionic hydration energy, and interfacial effects.