Strong Cation···π Interactions Promote the Capture of Metal Ions within Metal-Seamed Nanocapsule

Thallium ions are transported to the interior of gallium-seamed pyrogallol[4]­arene nanocapsules. In comparison to the capture of Cs ions, the extent of which depends on the type and position of the anion employed in the cesium salt, the enhanced strength of Tl···π vs Cs···π interactions facilitates permanent entrapment of Tl+ ions on the capsule interior. “Stitching-up” the capsule seam with a tertiary metal (Zn, Rb, or K) affords new trimetallic nanocapsules in solid state.