Large fullerenes stabilized by encapsulation of metallic clusters

Area of Science:

• Fullerene chemistry
• Materials science
• Computational chemistry

Background:

• Endohedral metallofullerenes (EMFs) are fullerenes encapsulating metal atoms.
• Large carbon cages (C92-C100) offer unique electronic properties.
• Understanding EMF structures is crucial for their applications.

Purpose of the Study:

• To propose stable structural models for six EMFs with large carbon cages (C92-C100).
• To investigate the electronic properties influencing EMF stability.
• To correlate structural features with electron transfer dynamics.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis of the energy gap between the fourth and third lowest unoccupied molecular orbitals (LUMO-4 and LUMO-3).
• Assessment of formal electron transfer to the carbon cages.

Main Results:

• Proposed structures for six endohedral metallofullerenes (C92-C100).
• Identified a sizeable (LUMO-4)-(LUMO-3) energy gap in the proposed structures.
• Demonstrated a formal transfer of six electrons to the carbon cages in these EMFs.

Conclusions:

• The proposed structures are likely stable based on electronic criteria.
• The (LUMO-4)-(LUMO-3) gap serves as a key indicator for EMF stability.
• Six-electron transfer is a significant factor in the stabilization of these large-cage EMFs.