Methodological Investigation for Hydrogen Addition to Small Cage Carbon Fullerenes

Abstract

Hydrogenated small fullerenes (Cn, n < 60) are of interest as potential astrochemical species, and as intermediates in hydrogen-catalysed fullerene growth. However, the computational identification of key stable species is difficult due to the vast configurationally space of structures. In this study, we explored routes to predict stable hydrogenated small fullerenes. We showed that neither local fullerene geometry nor local electronic structure analysis was able to correctly predict subsequent low-energy hydrogenation sites, and sequential stable addition searches also sometimes failed to identify most stable hydrogenated fullerene isomers. Of the empirical and semi-empirical methods tested, GFN2-xTB consistently gave highly accurate energy correlations (r > 0.99) to full DFT-LDA calculations at a fraction of the computational cost. This allowed identification of the most stable hydrogenated fullerenes up to 4H for four fullerenes, namely two isomers of C28 and C40, via “brute force” systematic testing of all symmetry-inequivalent combinations. The approach shows promise for wider systematic studies of smaller hydrogenated fullerenes.

Gas-phase C60Hn+q (n = 0–4, q = 0,1) fullerenes and fulleranes: spectroscopic simulations shed light on cosmic molecular structures

“…32 Similar methods were applied in the study of hydrogenation of small carbon cages. 33 To contribute to our ulterior goal of proposing new C 60 H n + q candidates for astronomical detection, we have derived spectroscopic data in the ultraviolet (UV) and infrared (IR) regions. These data hold the potential to assist in future astronomical searches, including those conducted with advanced instruments like the james webb space telescope (JWST).…”

Thermal treatment of water-soluble particles formed by compounds composed of carbon nanobelts and C60 molecules

“…A carbon nanobelt (CNB) is a loop of fused benzene rings and various types of CNBs have been successfully synthesised in recent years 1 – 7 . The structures of CNBs, structural transitions and the effect of external electric fields on the structures of CNBs have been theoretically and numerically analysed 8 – 11 and several devices, in which CNBs are used, have been designed and developed 12 – 14 . A C 60 molecule is one form of fullerenes composed of 60 carbon atoms 15 .…”