A Diverse Array of Large Capsules Transform in Response to Stimuli

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Allosteric regulation allows biomolecules like enzymes to change conformation and function in response to stimuli.
• Synthetic coordination cages can mimic this adaptability by altering structure via dynamic metal-ligand bonds.

Purpose of the Study:

• To demonstrate an abiological system of zinc coordination cages that exhibit complex structural transformations in response to simple chemical stimuli.
• To explore the network of cage transformations and their potential for creating adaptable synthetic hosts.

Main Methods:

• Utilized zinc(II) ions and specific organic subcomponents to construct coordination cages.
• Applied chemical stimuli, including different aldehydes and a chiral template guest, to induce cage transformations.
• Investigated structural changes through crystallization and characterization.

Main Results:

• A Zn20L12 dodecahedron transformed into a larger Zn30L12 icosidodecahedron via subcomponent exchange.
• In the presence of a chiral guest, the system self-assembled into a Zn15L6 truncated rhombohedral architecture.
• Further guest-induced crystallization yielded an unprecedented Zn20L8 pseudo-truncated octahedral structure from existing cages.

Conclusions:

• Demonstrated a versatile synthetic coordination cage system capable of complex structural adaptation.
• Showcased how chemical stimuli can trigger predictable transformations between different cage architectures.
• Highlighted the potential for designing adaptable synthetic hosts with tunable functionalities for diverse applications.