Introducing “carborazine” as a novel heterocyclic aromatic species

Abstract

Borazine is regarded as inorganic benzene, possessing a number of features analogous to aromatic benzene. The aromaticity of borazine, however, is a controversial matter to date. We propose a new heterocyclic species by introducing C, B and N atoms at opposite faces of a six-membered ring. This novel species, which we refer to as “carborazine,” possesses C_2h symmetry, and more importantly it is aromatic. The aromaticity of carborazine is established by NICS values and supported by a number of topological parameters. Unlike borazine and benzene, carborazine possesses non-degenerate molecular orbitals and a relatively smaller HOMO–LUMO gap. Finally, we show the formation of phenol, aniline (by substitution) and naphthalene analogues (by fusion) of carborazine, which may suggest that a new class of heterocyclic species can be obtained using carborazine as building block.