A ferrocene-based pseudopeptide chiroptical switch.

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Ferrocene-containing molecules are known for their unique electronic and redox properties.
• Chirality in supramolecular assemblies can be sensitive to environmental changes.
• Stimuli-responsive molecular switches are crucial for developing advanced functional materials.

Purpose of the Study:

• To synthesize and characterize a double-stranded ferrocene pseudopeptide.
• To investigate the stimuli-responsive chirality inversion of the synthesized compound.
• To explore its potential as a molecular chiroptical switch.

Main Methods:

• Synthesis of the double-stranded ferrocene pseudopeptide (2b).
• Chirality analysis using Circular Dichroism (CD) spectroscopy.
• Investigation of stimuli-induced changes (solvent exchange, acid addition) on the compound's structure and properties.
• Oligomerization and hydrogen bonding analysis.

Main Results:

• Compound 2b exhibits reversible chirality inversion upon solvent exchange or acid addition.
• The molecule self-assembles into fast-exchanging oligomers, forming a chiroptical switch with two stable states.
• Ferrocene group inversion leads to a distinct CD signal in the visible spectrum.
• Chirality inversion is driven by conformational changes and rearrangements in hydrogen bonding.

Conclusions:

• The developed ferrocene pseudopeptide functions as an effective chiroptical switch.
• Stimuli-responsive chirality inversion is achieved through controlled conformational and hydrogen bonding changes.
• This work opens avenues for designing sophisticated molecular switches and responsive systems.