Theoretical Studies on Actinides(U and Cm) Endohedral Borospherenes

The recently discovered all-boron fullerene(D_2d B^-/0₄₀) opened a new chapter in borospherene chemistry. Similar to fullerenes, metal doping is also an important way for modification and functionalization of borospherenes. This work predicts a series of stable actinide metal-doped borospherenes ［An@B₃₉］ⁿ⁺ (An=U, n=3; An=Cm, n=2) by using density functional theory. Theoretical calculations show that these borospherenes are all endohedral borospherenes, among which the lowest energy structures of ［U@B₃₉］³⁺ has C₃ symmetry, while ［Cm@B₃₉］²⁺ is a C₁ structure. Bonding nature analysis shows that delocalized σ and π bonds exist in ［U@B₃₉］³⁺ and ［Cm@B₃₉］²⁺. In addition, the covalent interaction of the U-B bond in ［An@B₃₉］ⁿ⁺ is stronger than that of the Cm-B bond. Therefore, the covalency in the An-B bonds may be essential for the formation of these metal-doped borospherenes. This work expands the borospherenes system and provides theoretical clues for the design of novel stable metal endohedral borospherenes.