Theoretical Insight into Complexation Between Cyclocarbons and C₆₀ Fullerene

This work conducts a comprehensive theoretical study on the non-covalent complexation between cyclocarbons and C₆₀ fullerene for the first time. The binding energy between cyclocarbons and C₆₀ fullerene is significantly stronger than that between two C₁₈ or two C₆₀ fullerenes, indicating a particularly strong affinity. The cyclocarbons and C₆₀ 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 C₆₀ fullerene increases almost linearly with the increase of cyclocarbon size, and the C₃₄@C₆₀ 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 C₆₀ fullerene gradually decreases. In C₆₀@2 C₃₄ trimer, the fullerene is symmetrically surrounded by two cyclocarbons. The results on the trimers formed by cyclocarbon and C₆₀ 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".