Construction of cucurbit[7]uril based tubular nanochannels incorporating associated [CdCl4]2- and lanthanide ions.

There is intensive interest in the design of tubular channels because of their novel structures and various applications in a variety of research fields. Herein, we present a series of coordination-driven Q[7]-derived organic nanochannels using an anion-induced strategy under different acid concentrations. An advantage of this approach is that the tubular channels not only retain the original character of the parent macrocyclic receptors but also provide deep hydrophobic cavities possessing guest binding sites. Importantly, this study also emphasizes the efficiency of the macrocyclic receptors in providing a tubular hydrophobic cavity by directly stacking on top of one another with the anion-fixed and by acid control. The resulting combination of hydrogen bonding, C-H···Cl, and ion-dipole interactions helps to stabilize these supramolecular architectures. Such systems are both tunable and versatile and allow for interconvertibility in the construction of nanochannels based on these macrocyclic receptors.