Metal-metal bonds inside fullerenes.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Inorganic Chemistry

Background:

• Fullerenes offer hollow interiors ideal for encapsulating metal ions, forming endohedral metallofullerenes (EMFs).
• The confinement effect within carbon cages and electron transfer stabilize multiple metal ions, overcoming repulsion.
• EMFs serve as excellent models for investigating metal-metal bonding, particularly involving f-block elements.

Purpose of the Study:

• To review recent experimental and theoretical advancements in metal-metal bonds within EMFs.
• To explore homonuclear, heteronuclear, and multicenter bonding involving lanthanide and actinide metals.
• To discuss the potential applications of EMFs with metal-metal bonds.

Main Methods:

• Experimental synthesis and characterization of EMFs.
• Theoretical calculations and computational modeling of electronic structure and bonding.
• Analysis of metal-metal bond types (homonuclear, heteronuclear, multicenter) in f-block EMFs.

Main Results:

• Discovery of unique metal-metal bonds, including homonuclear, heteronuclear, and multicenter types, involving f-block elements (lanthanides and actinides).
• Demonstration of EMFs as versatile platforms for studying the nature of f-block bonding.
• Identification of strong magnetic coupling and high stability in EMFs with metal-metal bonds.

Conclusions:

• EMFs provide unprecedented insights into f-block metal-metal bonding.
• The unique properties of EMFs with metal-metal bonds open avenues for advanced materials.
• Potential applications include single-molecule magnets and molecular spin qubits due to magnetic coupling and stability.