Anion-adaptive crystalline cationic material for (99)TcO(4)(−) trapping

Efficient anion recognition is of great significance for radioactive (99)TcO(4)(−) decontamination, but it remains a challenge for traditional sorbents. Herein, we put forward a tactic using soft crystalline cationic material with anion-adaptive dynamics for (99)TcO(4)(−) sequestration. A cucurbit[8]uril-based supramolecular metal-organic material is produced through a multi-component assembly strategy and used as a sorbent for effective trapping of TcO(4)(−). Excellent separation of TcO(4)(−)/ReO(4)(−) is demonstrated by fast removal kinetics, good sorption capacity and high distribution coefficient. Remarkably, the most superior selectivity among metal-organic materials reported so far, together with good hydrolytic stability, indicates potential for efficient TcO(4)(−) removal. The structure incorporating ReO(4)(−) reveals that the supramolecular framework undergoes adaptive reconstruction facilitating the effective accommodation of TcO(4)(−)/ReO(4)(−). The results highlight opportunities for development of soft anion-adaptive sorbents for highly selective anion decontamination.