A Dual Functional Molecular Tweezer: pH-Driven C₆₀ Capture/Release and Ba²⁺ Selective Recognition

Novel resorcin[4]arene-based molecular tweezers functionalized with dual benzo-crown-ether moieties were successfully synthesized. These macrocycles exhibit pH-responsive switching between vase and kite conformations, enabling the reversible encapsulation of C₆₀ under basic conditions primarily driven by dispersion-dominated interactions and efficient acid-triggered release. Remarkably, one of these macrocycles further demonstrates selective fluorescence sensing of barium ions, thus rendering this particular derivative a bifunctional system capable of integrating both fullerene recognition and cation detection in a single molecular architecture.