Ion-Responsive Supramolecular Assemblies in Aqueous Solutions

摘要

Deep-cavity cavitands are a class of molecules that can be used for multiple applications, including: regioselective reactions, catalysis, separations & selectivity, and kinetic protection. They have also proven useful as models for studying the Hofmeister and hydrophobic effects, in context. Herein, the synthesis of these molecules will be outlined, highlighting novel approaches for molecular diversity with the synthesis of inherently positively charged hosts, protic hosts, neutral and negatively charged hosts. The effect of structure modification to the rim of the hosts will be discussed with a supramolecular ion-responsive dimer-to-tetramer system. This system also demonstrates cation selectivity and the importance of discussing ion-ion and ion-hydrophobic interactions in context. Finally, two systems with octa-cationic hosts will be presented. The change of charge on the host has dramatic consequences to their assembly properties, with salting-in salts stabilizing them.