Functionalized O6-Corona[6]arenes: Synthesis, Structure, and Fullerene Complexation Property

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• On-corona[n]arenes are macrocyclic compounds with potential host-guest properties.
• Functionalization of macrocycles can tune their binding affinities and structural characteristics.

Purpose of the Study:

• To synthesize novel ester-containing and methoxymethyl-substituted On-corona[n]arenes (n=6, 8).
• To investigate the structural features and fullerene complexation abilities of these new macrocycles.

Main Methods:

• Fragment coupling strategy for macrocycle synthesis.
• Ester reduction using LiAlH4 followed by etherification.
• Spectroscopic characterization and X-ray crystallography.
• Binding studies with C60 and C70 fullerenes in toluene.

Main Results:

• Successful synthesis of functionalized On-corona[n]arenes (n=6, 8) in good yields.
• Macrocycles exhibit a unique corona-type conformation with a large cylindroid cavity.
• Strong 1:1 complex formation with C60 and C70 fullerenes observed.
• High association constants (up to 1.59 × 10^5 M⁻¹) for fullerene complexation were determined.

Conclusions:

• The synthesized On-corona[n]arenes are potent macrocyclic hosts for fullerenes.
• Their unique structure facilitates strong host-guest interactions.
• These findings open avenues for applications in molecular recognition and separation technologies.