The unique sandwich KBeBH cluster with a real borozene BH core.

Theoretical evidence is reported for a boron-based KBeBH sandwich cluster, showing a perfectly BH ring, being capped by two tetrahedral KBe ligands. Due to the comfortable charge transfer, the sandwich is viable in [KBe][BH][BeK] ionic complex in nature. The [BH] core with 6π aromaticity vividly imitates the benzene (CH), occurring as a real borozene. In contrast, the tetrahedral [KBe] 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.