Supramolecular Receptor Design: Anion‐Triggered Binding of C₆₀

Abstract

Seeing is believing: Treatment of a tetrathiafulvalene-functionalized calix[4]pyrrole 1 with chloride anions in CH2Cl2 produces bowl-like receptor 1⋅Cl−, which is able to encapsulate C60 in a 2:1 barrel-like manner. The color of C60⊂(1⋅Cl−)2 (green in CH2Cl2) differs dramatically from its constituents (yellow and magenta for 1 and C60, respectively), thus allowing its formation to be monitored visually.