B<sub>7</sub>Be<sub>6</sub>B<sub>7</sub>: A Boron‐Beryllium Sandwich Complex
Xue Dong, William Tiznado, Yu‐qian Liu, Luis Leyva‐Parra, Xinbo Liu, Sudip Pan, Gabriel Merino, Zhong‐hua Cui
Abstract
Abstract Planar boron clusters have often been regarded as “π‐analogous” to aromatic arenes because of their similar delocalized π‐bonding. However, unlike arenes such as C 5 H 5 − and C 6 H 6 , boron clusters have not previously shown the ability to form sandwich complexes. In this study, we present the first sandwich complex involving beryllium and boron, B 7 Be 6 B 7 . The global minimum of this combination adopts a unique architecture having a D 6 h geometry, featuring an unprecedented monocyclic Be 6 ring sandwiched between two quasi‐planar B 7 motifs. The thermochemical and kinetic stability of B 7 Be 6 B 7 can be attributed to strong electrostatic and covalent interactions between the fragments. Chemical bonding analysis shows that B 7 Be 6 B 7 can be considered as a [B 7 ] 3− [Be 6 ] 6+ [B 7 ] 3− complex. Moreover, there is a significant electron delocalization within this cluster, supported by the local diatropic contributions of the B 7 and Be 6 fragments.