C6h-Hexa-azahexaborine, [(CH)BN]6:: structure and magnetic properties of a proposed 18-electron aromatic ring

Heterocycles [(CH)BN](n), formally derived by insertion of a BN pair in the same sense on each edge of a (CH), ring, obey an n = (4m + 2) rule for closed n shells. The case n = 6 leads to a molecule with a planar geometry at the B3LYP/6-31G** level and a significant continuous diatropic ring current according to a distributed gauge calculation at the CHF level in the 6-31G** basis. On this magnetic criterion C-6h-hexa-azahexaborine can be predicted to be an aromatic system.