Chlorofullerenes featuring triple sequentially fused pentagons

Area of Science:

• Fullerene chemistry
• Supramolecular chemistry
• Materials science

Background:

• The triple sequentially fused pentagons (TSFP) motif is a fundamental fullerene subunit.
• TSFP violates the isolated pentagon rule (IPR) and has not been experimentally observed in carbon cages.
• The properties of TSFP-containing fullerenes remain largely unexplored.

Purpose of the Study:

• To synthesize and characterize novel fullerene derivatives incorporating the TSFP motif.
• To investigate the structural and electronic properties of these non-IPR fullerenes.
• To explore the reactivity and potential applications of TSFP-based carbon cages.

Main Methods:

• Synthesis of four chlorinated derivatives of three distinct fullerene cages featuring the TSFP motif.
• X-ray crystallographic analysis to determine molecular structures.
• Density functional theory (DFT) calculations for theoretical rationalization.

Main Results:

• Successful synthesis and characterization of chlorinated TSFP fullerenes.
• X-ray crystallography revealed significant relief of molecular strain upon chlorination.
• Derivatives exhibit unique reactivity due to unsaturated pentagon fusion sites, leading to chirality.
• DFT calculations support the observed reactivity patterns.

Conclusions:

• Chlorination effectively stabilizes and modifies the properties of TSFP-containing fullerenes.
• The unique reactivity of these compounds contrasts with other non-IPR fullerenes.
• These findings are expected to stimulate further theoretical and experimental investigations into TSFP fullerene chemistry.