Fig. 1
From: Anion-adaptive crystalline cationic material for 99TcO4− trapping
Design strategies for introducing anion-adaptive capability to sorbent materials. a Direct modification of organic polymers or metal–organic sorbents with macrocyclic motifs bearing anion-recognition ability (orange lines: backbones of solid sorbents; green circles: anion receptors; purple balls marked as “A”: anions; blue balls marked as “M”: metal nodes). b Supramolecular assembly of smart polymers or metal–organic sorbents exhibiting anion-adaptive behaviors (orange lines: backbones of solid sorbents; green curves: anion-recognition sites; purple circles: anions; blue balls: metal nodes). c Glycoluril-based macrocyclic hosts for anion recognition through two different modes (purple balls: anions). d Dual roles of CB8 in accomplishing both the construction of a supramolecular network by encapsulation and providing outer-surface interaction sites for anion recognition: left, a full view of CB8-based supramolecular framework; right: enlarged diagram of CB8 showing its interactions with the surrounding components (red balls: O atoms; light-blue balls: C atom; dark blue balls: N atoms)
