Evolution spectrum of C60 isomers in buffer gas

Area of Science:

• Fullerenes research
• Computational chemistry
• Materials science

Background:

• Fullerenes, like C60, are carbon allotropes with unique electronic and structural properties.
• Understanding fullerene isomer dynamics is key to controlling their properties and applications.
• Stone-Wales (SW) defects and heptagon formations significantly alter fullerene structures and stability.

Purpose of the Study:

• To investigate the energy spectrum and geometric stability of C60 nonclassic fullerenes with heptagon defects.
• To explore the role of these nonclassic isomers in the annealing dynamics of C60.
• To elucidate the mechanisms of structural transformations in fullerenes under thermal stress.

Main Methods:

• Calculation of energy spectra using the Brenner empirical potential.
• Geometric analysis of fullerene isomers.
• Molecular dynamic simulations of C60 evolution in Helium buffer gas at 2500 K.

Main Results:

• The energy spectrum of C60 nonclassic fullerenes with heptagon defects submerges into that of classic fullerenes.
• Nonclassic fullerene isomers are more attainable at higher Stone-Wales (SW) defect stacks.
• Molecular dynamics revealed that nonclassic fullerenes are vital in C60 annealing, with SW transitions occurring at lower SW stacks and a novel non-SW multistep rearrangement observed.

Conclusions:

• Nonclassic fullerenes with heptagon defects are energetically comparable to classic fullerenes and can be more easily formed at higher SW defect levels.
• These nonclassic isomers are critical intermediates in the thermal annealing process of C60.
• The study identified a new type of multistep rearrangement mechanism in fullerene structural evolution.