Lithium selectivity of crown ethers: The effect of heteroatoms and cavity size

Insights into adsorbent materials for lithium extraction by capacitive deionization: reconceptualizing the role of materials informatics

“…The critical determinant of ionic selectivity lies in the relationship between the size of the CE cavity and ionic radius. 49 Appropriate modication strategies, including structural adjustment and morphological improvement, 51 have been instrumental in optimizing the adsorption capacity of specic CEs while ensuring their sustained selectivity for lithium ions. 52 Specically, structural adjustment requires techniques including element doping, functional group diversication, vacancy construction, and others.…”

“…For instance, Iklima Oral et al investigated the selective complexation of Li + over other metal ions by DFT calculations, for 15-, 12-, and 9-membered CEs and their derivatives, where the best selectivity of Li + over Mg 2+ was achieved by thio-benzo-15-crown-5. 49 Experimental studies and DFT calculations conducted by Torrejos et al revealed that CEs with small cavity sizes exhibited good selectivity, whereas the larger radius of M + (M + = Li + , Na + , K + ) coordinated with bulky structures and larger O-M + distances hindered effective adsorption. 84…”

“…As a size-based ion-selective material, CEs possessing cavities of comparable sizes to lithium ions are selected because of their distinct properties. 47 Typical examples of selective CEs include 15-crown-5, 48 9-crown-3, 49 12-crown-4, 50 benzo-15-crown-5, 51 etc. The critical determinant of ionic selectivity lies in the relationship between the size of the CE cavity and ionic radius.…”

Recovery of Brine Resources Through Crown-Passivated Graphene, Silicene, and Boron Nitride Nanosheets Based on Machine-Learning Structural Predictions

“…The use of crown ethers (CEs) for the host–guest selective binding and recovery of metal ions in various media has continued to evolve over the years. − The unique structure of the CEs often drives their complexation with the metal ions, leading to strong ion–dipole interactions. The strength and stability of the complexes depends on the crown pore size, the size and charge of the metal ions and the nature of the solvating medium. , With the emergence of the nanopore technology, single-ion channels of CEs have been created on several two-dimensional (2D) materials for various applications ranging from the recovery of metal ions in aqueous media − to energy storage applications. , The incorporation of the CEs afforded the creation of hybrid 2D-CE materials, which retain both the unique features of the 2D materials such as high carrier mobility and high surface area and the charge polarization within the crown cavities for the selective recovery of various ions.…”

Thermodynamic study of crown ether–lithium/magnesium complexes based on benz-1,4-dioxane and its homologues

“…10,13–16 Different cavity sizes, heteroatoms within the ring such as nitrogen or sulfur, substituents, and complex stoichiometries have been investigated. 17–20 To remove the metal ions from the CE–metal complex, a temperature increase in the system releases the ions from this complex, as shown in the work of Warshawsky and Kahana. 21…”