Anion-adaptive crystalline cationic material for TcO trapping.

Efficient anion recognition is of great significance for radioactive TcO 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 TcO 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. Excellent separation of TcO/ReO 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 removal. The structure incorporating ReO reveals that the supramolecular framework undergoes adaptive reconstruction facilitating the effective accommodation of TcO/ReO. The results highlight opportunities for development of soft anion-adaptive sorbents for highly selective anion decontamination.