Induced-fit or conformational selection is of profound significance in biological regulation. Biological receptors alter their conformation to respond to the shape and electrostatic surfaces of guest molecules. Here we report a water-soluble artificial molecular host that can sensitively respond to the size, shape, and charged state of guest molecules. The molecular host, i.e. nanocube, is an assembled structure consisting of six gear-shaped amphiphiles (GSAs). This nanocube can expand or contract its size upon the encapsulation of neutral and anionic guest molecules with a volume ranging from 74 to 535 Å3 by induced-fit. The responding property of this nanocube, reminiscent of a feature of biological molecules, arises from the fact that the GSAs in the nanocubes are connected to each other only through the hydrophobic effect and very weak intermolecular interactions such as van der Waals and cation-π interactions.

Proteins in hyperthermophiles exhibit extremely high thermal stability unlike general proteins. These thermostable proteins are stabilized by weak molecular interactions such as hydrogen bonding, charge interactions and van der Waals (vdW) interactions, along with the hydrophobic effect. An in-depth understanding of the stabilization mechanisms will enable us to rationally design artificial molecules with very high thermal stability. Here we show thermally stable supramolecular assemblies composed of six identical amphiphilic molecules having an indented hydrophobic surface, held together by weak intermolecular interactions (vdW and cation-π interactions) and the hydrophobic effect in water. The disassembly temperature of one of the assemblies is over 150°C, which is higher than that of the most hyperthermophilic protein reported to date (PhCutA1). Study of the relationship between the structure of the components and the stability of the assemblies indicates that the hyperthermostability is achieved only if all the weak interactions and the hydrophobic effect work cooperatively.

Spontaneous formation of the heteroleptic cadmium(II) bis(terpyridine) complex under ambient conditions can be achieved by a combination of 6,6''-di(2,6-dimethoxylphenyl)-substituted and unsubstituted terpyridine-based ligands. Building on this dynamic heteroleptic complexation, diverse metallo-supramolecular macrocycles and cages were readily assembled in quantitative yields from the predesigned multicomponent systems. The complementary ligation reinforced self-recognition to facilitate the shape-dependent self-sorting of a four-component dynamic library into two well-defined parallelograms. In addition, the subtle lability difference between homoleptic and heteroleptic complexes led to the site-selective Cd -Zn transmetalation in the Sierpiński triangle. Facile construction of a dodecanuclear tetrahedral metallocage was also realized by using two self-recognizable tritopic building blocks. The photophysical study of the metallo-supramolecules assembled from the d metal ions revealed intense ligand-based photoluminescence in solution. The self-assembly strategy described here provides an efficient methodology for building pre-programmable, sophisticated supramolecular architectures furnished with photoactivity.