The unique sandwich K(6)Be(2)B(6)H(6) cluster with a real borozene B(6)H(6) core

Theoretical evidence is reported for a boron-based K(6)Be(2)B(6)H(6) sandwich cluster, showing a perfectly D(6h) B(6)H(6) ring, being capped by two tetrahedral K(3)Be ligands. Due to the comfortable charge transfer, the sandwich is viable in [K(3)Be](3+)[B(6)H(6)](6−)[BeK(3)](3+) ionic complex in nature. The [B(6)H(6)](6−) core with 6π aromaticity vividly imitates the benzene (C(6)H(6)), occurring as a real borozene. In contrast, the tetrahedral [K(3)Be](3+) ligand is 2σ three-dimensional aromatic, acting as the simple superatom. Thus, this complex possesses a collectively three-fold 2σ/6π/2σ aromaticity. The interlaminar interaction is governed by the robust electrostatic attraction. The unique chemical bonding gives rise to interesting dynamic fluxionality.