Sulfate Anion as a pH-Switchable Template: Three-State Switchable Systems Based on Diamidocarbazoles

摘要

The sulfate anion SO42- - one of the most powerful and versatile anionic templates - can be reversibly switched off in aprotic solvents by protonation to the very weakly binding anion HSO4-. This sharp ON/OFF behaviour opens new opportunities for switching and manipulation of anion templated supramolecular systems, such as reversible folding/unfolding, assembly/disassembly or induction of mechanical motions. As a proof of concept, two new acid/base switchable three-state systems are presented here.