Chiral Truxene‐Based Self‐Assembled Cages: Triple Interlocking and Supramolecular Chirogenesis
Résumé
Incorporating chiral elements in host–guest systems currently attracts much attention because of the major impact such structures may have in a wide range of applications, from pharmaceuticals to materials science and beyond. Moreover, the development of multi‐responsive and ‐functional systems is highly desirable since they offer numerous benefits. In this context, we describe herein the construction of a metal‐driven self‐assembled cage that associates a chiral truxene‐based ligand and a bis‐ruthenium complex. The maximum separation between both facing chiral units in the assembly is fixed by the intermetallic distance within the lateral bis‐ruthenium complex (8.4 Å). The resulting chiral cavity was shown to encapsulate polyaromatic guest molecules, but also to afford a chiral triply interlocked [2]catenane structure. The formation of the latter occurs at high concentration, while its disassembly could be achieved by the addition of a planar achiral molecule. Interestingly the planar achiral molecule exhibits induced circular dichroism signature when trapped within the chiral cavity, thus demonstrating the ability of the cage to induce supramolecular chirogenesis.