Hidden in Plain Sight: Aromaticity of Hexagonal Boron Nitride

Abstract

Hexagonal boron nitride (hBN) and graphene are similar in many ways - they are isoelectronic, have the same structure, are chemically inert and show persistence. All of these properties are indicators of a deeper connection that has, thus far, been overlooked. Unlike graphene, which has been shown to be aromatic, it is not known if hBN is aromatic. In this density functional theory-based work, we investigate the aromaticity (or lack thereof ) of hBN. By employing the magnetic criterion, supported by group theoretic and energetic considerations, we show that hexagonal boron nitride is indeed aromatic, even if weakly so, as compared to graphene. Since aromaticity is used to understand physical and chemical properties of planar compounds, the picture developed in this work is important to bridging the gap between the physical and chemical understanding of hBN's properties.