Self-assembly, [1] nowadays recognized as one of the most promising techniques for building nanoscale structures, [2] is nature's favorite way of building objects, probably because it is the most economic and reliable strategy. Life is made possible by highly complex functional structures built with great perfection by self-assembly, which allows for errors to be minimized and/or spontaneously corrected. [3] The same supramolecular principles have made it possible to assemble synthetic building blocks into predictable assemblies. [4] However, the organizational complexity and control found in biological structures for the creation of recognition sites is still far beyond the ability of chemists. Building complex synthetic structures with specific function through self-assembly remains a challenge. [5] One of the more intriguing aspects of biological and chemical self-assembly is the capture and organization of guest molecules in self-assembled cages and capsules. [6] The entrapment of guest molecules in synthetic self-assembled systems is mainly achieved by steric constraints in rigid preorganized building blocks. Bulky solvents that cannot occupy the cavities are used for efficient encapsulation of guests. There are few examples where the self-organization of the enclosure occurs through noncovalent interactions. [7] Furthermore, supramolecular systems with higher hierarchy of assembly in both the host and guest obtained through the use of the same type of noncovalent interactions were until now unknown.
Here we report a dynamic self-assembled system where the reversibility of the association allows changes in the constitution by all of the most characteristic processes of supramolecular chemistry, namely, internal rearrangement, [