Designing and Analyzing Crown Ether Resorcin[4]arene Cavitands For Induced Conformational Binding Interactions

This field of study entails the synthesis of resorcin[4]arene-derived cavitands, container molecules with an enforced cavity that can undergo reversible conformational switching for  molecular recognition. Previous studies demonstrated that although cavitands with quinoxaline moieties contain concave surfaces available for guest inclusion, their flexible framework prevents guest binding. This problem spawned the idea of partially substituting quinoxaline moieties with crown ethers, which are widely known for their selective recognition of cationic, anionic and neutral species. We hypothesize that the synthesis of crown incorporated quinoxaline cavitands can improve rigidity, and enhance binding of guests. We developed a versatile synthesis of resorcin[4]arene-based crown ether cavitands. Our cavitands are characterized by nuclear magnetic resonance spectroscopy and single crystal X-Ray diffraction. We are exploring the incorporation of different crown sizes to tailor host-guest binding and modulate the cavitand switching mechanism. We expect to observe molecular switching behavior with guest complexation and also obtain crystal structures of these cavitands. By understanding the behaviors of the host-guest interactions, more elaborate crown incorporated resorcin[4]arene cavitands can be designed to mimic enzymes substrate interactions and toxic remediation.