Crystalline functionalized endohedral C₆₀ metallofullerides

Area of Science:

• Nanotechnology
• Materials Science
• Supramolecular Chemistry

Background:

• Endohedral metallofullerenes (EMFs) are molecules with metal atoms encapsulated inside fullerene cages.
• Studies have primarily focused on larger fullerenes (e.g., C82) due to the high reactivity of smaller C60-based EMFs.
• Stabilization of C60-based EMFs is crucial for their detailed investigation.

Purpose of the Study:

• To synthesize and characterize novel functionalized C60-based metallofullerenes.
• To determine the structure and electromagnetic properties of these stabilized EMFs.
• To investigate the effect of chemical functionalization on EMF stability and properties.

Main Methods:

• Chemical functionalization of C60 with trifluoromethyl (CF3) groups.
• Encapsulation of Gadolinium (Gd) and Lanthanum (La) metal atoms within C60 cages.
• Synchrotron X-ray single-crystal diffraction for structural determination.
• Electromagnetic property measurements, including magnetic susceptibility.

Main Results:

• Successful isolation and structural determination of crystalline Gd@C60(CF3)5 and La@C60(CF3)5.
• X-ray diffraction confirmed the encapsulation of La and Gd atoms within the I h -C60 fullerene cage.
• Trifluoromethyl functionalization significantly widened the Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital (HOMO-LUMO) gap.
• Weak antiferromagnetic coupling was observed in Gd@C60(CF3)3 crystals at low temperatures.

Conclusions:

• Chemical functionalization is an effective strategy to stabilize reactive C60-based metallofullerenes.
• The synthesized functionalized EMFs exhibit unique structural and electromagnetic properties.
• This work opens new avenues for exploring C60-based EMFs in various applications.