Mapping the structural diversity of C60 carbon clusters and their infrared spectra

Abstract

The current debate about the nature of the carbonaceous material carrying the infrared (IR) emission spectra of planetary and proto-planetary nebulae, including the broad plateaus, calls for further studies on the interplay between structure and spectroscopy of carbon-based compounds of astrophysical interest. The recent observation of C60 buckminsterfullerene in space suggests that carbon clusters of similar size may also be relevant. In the present work, broad statistical samples of C60 isomers were computationally determined without any bias using a reactive force field, their IR spectra being subsequently obtained following local optimization with the density-functional-based tight-binding theory. Structural analysis reveals four main structural families identified as cages, planar polycyclic aromatics, pretzels, and branched. Comparison with available astronomical spectra indicates that only the cage family could contribute to the plateau observed in the 6-9 micron region. The present framework shows great promise to explore and relate structural and spectroscopic features in more diverse and possibly hydrogenated carbonaceous compounds, in relation with astronomical observations.

References in corpus (14)

• Infrared Emission from Interstellar Dust. I. Stochastic Heating of Small Grains
• Formation of buckminsterfullerene (C60) in interstellar space
• C${}_{60}$ in Reflection Nebulae
• Formation of fullerenes in H-containing Planetary Nebulae
• Laboratory formation of fullerenes from PAHs: Top-down interstellar chemistry
• Top-down formation of fullerenes in the interstellar medium
• The formation of fullerenes: clues from new C60, C70, and (possible) planar C24 detections in Magellanic Cloud Planetary Nebulae
• Are C60 molecules detectable in circumstellar shells of R Coronae Borealis stars?
• Infrared Study of Fullerene Planetary Nebulae
• Interstellar Fullerene Compounds and Diffuse Interstellar Bands
• On the Excitation and Formation of Circumstellar Fullerenes
• Searching for stable fullerenes in space with computational chemistry
• Transformation of amorphous carbon clusters to fullerenes
• Simulating the structural diversity of carbon clusters across the planar to fullerene transition

Cited by in corpus (2)

• Hydrogenation of C${}_{24}$ carbon clusters : structural diversity and energetic properties
• Finite-temperature stability of hydrocarbons: fullerenes versus flakes