Probing the Effect of Nitrogen and Boron Doping on Structures, Properties, and Stability of C20 Clusters

Fullerenes are carbon molecules arranged in a closed hollow shell to form spherical-like structures. These clusters exist in various sizes, Cn, with the smallest being C20. C20, often when doped with other elements, has shown promise in creating new materials as a catalyst and as energy storage material. Here, we look at the existence of C20 doped with nitrogen or boron atoms using density functional theory (DFT). C20 is doped with one to three boron or nitrogen atoms, respectively, including the five different C18N2 / C18B2 isomers. We examine detection of these compounds using infrared and Raman spectroscopy. Our calculations show all real vibrational frequencies (positive values) for each molecule, indicating their ability to form stable compounds. The stability of singlet and triplet states of C18N2 and C18B2 isomers is also evaluated in terms of HOMO-LUMO gap. Our preliminary calculations show that the singlet states of C18N2 isomers are lower in energy compared to the triplet states, except of one highly symmetric isomer. This work contributes to a better understanding of molecular structure of nanomaterials that can be used for adsorption of small gas-phase molecules, such as CO and NO2