Theoretical Insight into Complexation Between Cyclocarbons and C Fullerene.

This work conducts a comprehensive theoretical study on the non-covalent complexation between cyclocarbons and C fullerene for the first time. The binding energy between cyclocarbons and C fullerene is significantly stronger than that between two C or two C fullerenes, indicating a particularly strong affinity. The cyclocarbons and C fullerene can spontaneously assemble into complexes in the gas phase at room temperature, and the hydrophobic effect caused by the solvent environment can promote this binding. The binding strength with C fullerene increases almost linearly with the increase of cyclocarbon size, and the C@C dimer exhibits a perfect nano-Saturn structure. As the ring size increases, the angle between the two cyclocarbons of the 2 : 1 trimers formed by cyclocarbons and C fullerene gradually decreases. In C@2 C trimer, the fullerene is symmetrically surrounded by two cyclocarbons. The results on the trimers formed by cyclocarbon and C fullerenes in a 1 : 2 ratio showed when the cyclocarbon sandwiched between two fullerenes is not quite large, the trimers exhibit an ideal dumbbell-like structure, and the presence of the first fullerene has a significant synergistic effect on the binding of the second one. The cyclocarbon greatly promotes the dimerization of fullerenes, which acted as a "molecular glue".