Non‐Covalent Interactions Enable the Length‐Controlled Generation of Discrete Tubes Capable of Guest Exchange

Supramolecular chemistry in confined spaces constructed from macrocyclic molecules has attracted much attention because it can utilize the specific binding properties of macrocyclic cavities. Herein we report the preparation of length‐controlled discrete tubular structures by homo‐/co‐assembly of rim‐differentiated and peralkylamino‐substituted pillar[5]arenes via hydrogen bonds and salt bridges. By dimerization and trimerization, the expanded tubes show a fivefold helical structure and stepwise binding, respectively. We found that the exchange speed of guest molecules in the tubes could be controlled by varying the tube length. Hydrogen bonds and salt bridges enable the length‐controlled generation of discrete tubular structures from rim‐differentiated and peralkylamino‐substituted pillar[5]arenes. The speed of guest molecule exchange in the tubes depends on the tube length.