Search

The iconic caged shape of fullerenes gives rise to a series of unique chemical and physical properties; hence a deeper understanding of the attractive and repulsive forces between two buckyballs can bring detrimental information about the structural stability of such complexes, providing significant data applicable for several studies. The potential energy curves for the interaction of multiple van der Waals buckyball complexes with increasing mass were theoretically obtained within the DFT framework at ωB97xD/6-31G(d) compound model. These potential energy curves were employed to estimate the spectroscopic constants and the lifetime of the fullerene complexes with the Discrete Variable Representation and with the Dunham approaches. It was revealed that both methods are compatible in determining the rovibrational structure of the dimers and that they are genuinely stable, i.e., long-lived complexes. To further inquire into the nature of such interaction, Bader's QTAIM approach was applied. QTAIM descriptors indicate that the interactions of these closed-shell systems are dominated by weak van der Waals forces. This non-covalent interaction character was confirmed by the RDG analysis scheme. Indirectly, QTAIM also allowed us to confirm the stability of the non-covalent bonded fullerene dimers. Our lifetime calculations have shown that the studied dimers are stable for more than 1 ps, which increases accordingly with the number of carbon atoms.

In this work, a theoretical investigation of the effects caused by the doping of C 20 with silicon (Si) atom as well as the adsorption of CO, CO 2 and N 2 gases to C 20 and C 19 Si fullerenes was carried out. In concordance with previous studies, it was found that the choice of the doping site can control the structural, electronic, and energetic characteristics of the C 19 Si system. The ability of C 20 and C 19 Si to adsorb CO, CO 2 and N 2 gas molecules was evaluated. In order to modulate the process of adsorption of these chemical species to C 19 Si, an externally oriented electric field was included in the theoretical calculations. It was observed that C 19 Si is highly selective with respect to CO adsorption. Upon the increase of the electric field intensity the adsorption energy was magnified correspondingly and that the interaction between CO and C 19 Si changes in nature from a physical adsorption to a partial covalent character interaction.