Mapping the structural diversity of C-60 carbon clusters and their infrared spectra
C Dubosq and C Falvo and F Calvo and M Rapacioli and P Parneix and T Pino and A Simon, ASTRONOMY & ASTROPHYSICS, 625, L11 (2019).
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 C-60 buckminsterfullerene in space suggests that carbon clusters of similar size may also be relevant. In the present work, broad statistical samples of C-60 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 mu m 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.
Return to Publications page