Bambusuril as an effective astatide sequestrating agent by hydrogen bonding

Herein, we report a molecular cage allowing strong chelation of the ²¹¹At radioanion. Propargylated bambus[6]uril shows good affinity towards iodide and astatide radiohalides, affording promising inclusion complexes that are stable in phosphate buffered saline and human serum. Density functional theory calculations support the presence of C-H⋯At non-covalent cooperative interactions governing the formation of astatinated cage complexes. To our knowledge, this work is the first to report ²¹¹At-labeling using encapsulation via hydrogen bonds, which opens new perspectives in the design of ²¹¹At^--based radiopharmaceuticals.