A Redox-Responsive Ferrocene-Based Capsule Displaying Unusual Encapsulation-Induced Charge-Transfer Interactions.

Area of Science:

• Supramolecular Chemistry
• Organometallic Chemistry
• Materials Science

Background:

• Multiferrocene assemblies have been explored for various applications.
• Encapsulation of guest molecules in aqueous environments presents challenges.
• Controlling the assembly and disassembly of supramolecular structures is crucial for dynamic systems.

Purpose of the Study:

• To synthesize and characterize a novel ferrocene-based capsule capable of self-assembly in water.
• To investigate the reversible assembly and disassembly of the capsule using redox stimuli.
• To evaluate the encapsulation efficiency of the capsule for organic/inorganic dyes and electron acceptors.

Main Methods:

• Spontaneous self-assembly of bent amphiphiles with ferrocene units in water.
• Chemical redox stimuli to induce reversible disassembly and assembly of the ferrocene capsule.
• Spectroscopic analysis (UV-Vis) to observe host-guest interactions and charge-transfer (CT) complex formation.

Main Results:

• A well-defined, highly condensed ferrocene-based capsule was quantitatively formed in water.
• The capsule demonstrated reversible assembly and disassembly under ambient conditions via redox control.
• Efficient encapsulation of dyes and electron acceptors (e.g., chloranil, TCNQ) was achieved, leading to visible to near-infrared charge-transfer bands (650-1350 nm).

Conclusions:

• The developed ferrocene capsule represents a new class of organometallic host systems.
• Redox-triggered host-guest interactions and charge-transfer phenomena were successfully demonstrated.
• This system offers potential for applications in sensing, catalysis, and molecular recognition in aqueous media.