Structural requirements for producing solvent-free room temperature liquid fullerenes

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Organic Chemistry

Background:

• Fullerenes (C60 and C70) are carbon allotropes with unique electronic properties.
• Developing solvent-free liquid fullerenes is challenging due to strong intermolecular forces.
• Functionalization is a key strategy to tune fullerene properties.

Purpose of the Study:

• To synthesize novel solvent-free liquid fullerene derivatives.
• To investigate the effect of alkyl chain length on the physical and electrochemical properties of fullerenes.
• To explore the relationship between molecular structure and macroscopic behavior.

Main Methods:

• Synthesis of C60 and C70 monoadducts using Prato conditions with 1,3,5-tris(alkyloxy)benzene substituents.
• Chromatographic purification to isolate components.
• Melting point determination and rheological measurements at 25 °C.
• Electrochemical activity analysis of liquid and solid phases.

Main Results:

• Successful synthesis of solvent-free liquid fullerenes with tunable properties.
• Medium alkyl chain lengths were identified as crucial for achieving room temperature fluidity.
• Longer alkyl chains reduced viscosity but could induce metastable solid phases.
• Liquid fullerenes exhibited superior electrochemical activity compared to their metastable solid counterparts.

Conclusions:

• Alkyl chain length is a critical determinant for the physical state and rheological behavior of fullerene derivatives.
• Solvent-free liquid fullerenes offer unique properties and enhanced electrochemical performance.
• This work provides a pathway for designing functional liquid carbon materials.