Be3B11- cluster: a dynamically fluxional beryllo-borospherene

The beryllium-doped Be3B11- cluster has two nearly isoenergetic isomers, adopting the smallest trihedral spherical geometries with a boron single-chain skeleton. The B-11 skeleton in the global minimum (C-2v, (1)A(1)) comprises three conjoined boron rings (one B-8/two B-7) on the waist, sharing two B-3 equilateral triangles at the top and bottom, respectively. However, the local minimum (C-s, (1)A ') has one deformed B-4 pyramid at the top. The drastic structural transformation of B-11 skeletons from perfectly planar B-11 clusters mainly profited from robust electrostatic interaction between Be atoms and B-11 skeletons. The dynamic simulations suggest that two species can interconvert via a novel mechanism, that is triangle-pyramid-triangle, which facilitates the free migration of boron atoms in the B-11 skeleton, thereby showing the fascinating dynamic fluxionality. The chemical bonding analyses reveal that the B-11 skeleton is covered by two types of delocalized pi bonds in an orthogonal direction, which leads to its spherical aromaticity.

Automated summary

The beryllium-doped Be3B11- cluster has two nearly isoenergetic isomers with different geometries. The structural transformation of the boron skeleton is enabled by the electrostatic interaction between beryllium atoms and the boron skeleton. This cluster exhibits dynamic fluxionality and spherical aromaticity due to the free migration of boron atoms and the presence of delocalized pi bonds.