Redox Assisted Reversible Aromaticity Transition Between 30π Hückel and 28π Möbius Dication of a Core-Modified...

Area of Science:

• Organic Chemistry
• Materials Science
• Theoretical Chemistry

Background:

• Hexaphyrins are macrocyclic compounds with tunable electronic properties.
• Aromaticity in conjugated systems is crucial for material applications.
• Controlling aromaticity through molecular design is a key challenge.

Purpose of the Study:

• To synthesize and characterize a novel Hückel aromatic hexaphyrin.
• To investigate the transformation of Hückel aromaticity to Möbius aromaticity.
• To explore the electronic properties and aromaticity switching in modified hexaphyrins.

Main Methods:

• Core-modification of hexaphyrin to incorporate pyrrole and furan rings.
• Two-electron ring oxidation using triflic acid or Meerwein salt.
• Spectroscopic techniques (e.g., NMR, UV-Vis) for characterization.
• Quantum chemical calculations to support experimental findings.

Main Results:

• Formation of a 30π Hückel aromatic hexaphyrin with a specific ring structure.
• Oxidation led to a 28π Möbius aromatic dication species.
• Demonstration of reversible aromaticity transition between Hückel and Möbius systems.
• Spectroscopic and computational evidence confirmed the structural and electronic changes.

Conclusions:

• Core-modification provides a route to Hückel aromatic hexaphyrins.
• Hexaphyrins can undergo reversible aromaticity switching upon oxidation.
• This study offers insights into the design of molecules with switchable electronic properties.