Abstract
Crown ethers, cyclodextrins, calix[n]arenes and cucurbit[n]urils are common examples of macrocycles and among them, the most recently reported is pillar[n]arenes. This versatile family of host molecules have attracted considerable attention in supramolecular chemistry due to their pillar shape, facile functionalization and tunable host-guest properties in different solvents. Moreover, pillar[n]arenes are stable to guest removal, giving solvent-free phases and resulting in permanent porous structures. Herein, we synthesized a novel A1/A2-difunctionalized pillar[5]arene that can undergo imine condensation reactions to form a porous organic cage.
Porous organic cages have gain considerable interest due to their high porosity, making them suitable for a wide range of applications such as molecular separation, adsorption and catalysis. To date, the intrinsic cavities of organic cages result from the combination of two differently shaped synthons. Here we report the first example of a porous organic cage with dual microporosity as a result of the incorporation of a pillar[5]arene as one of the building units, leading to a new highly guest-responsive material.