Structural connectivity and formation mechanism of monometallic cluster fullerenes YCN@Cn (n = 68–84)

Excited by the recently experimental reports of monometallic cluster fullerenes, we examined the electronic and geometrical properties of monometallic cluster fullerenes YCN@Cn with size from C68 to C84 by density functional theory and statistical thermodynamic calculations. The calculations demonstrate that the thermodynamically favored isomers of YCN@Cn are in good agreement with available experimental results. Morphology analysis shows that the lowest‐energy YCN@Cn species are structurally connected by C2 insertion/extrusion and Stone–Wales rotation, which can be promoted under high temperature; enthalpy–entropy interplay can change the relative abundances of low‐energy isomers significantly at high temperature. All the results suggest that there is a structural evolution among these metallic cluster fullerenes in discharge condition, and thus, can rationalize their structural diversity in the soot and partly disclose their formation mechanism. The geometrical structures, electronic properties of these endohedral fullerene were discussed in detail. First‐principles calculations can be used to provide insight into the electronic and geometrical properties of monometallic cluster fullerenes. The lowest‐energy YCN@Cn species (n = 68–84) are found to be structurally connected by C2 insertion/extrusion and Stone–Wales rotation, indicating a structural evolution among these metallic cluster fullerenes in discharge condition.