Abstract

The double-arom. character of selected monocyclic carbon, boron, and borocarbon rings is demonstrated by refined nucleus-independent chem. shift (NICS) analyses involving the contributions of individual canonical MOs and their out-of-plane NICS tensor component (CMO-NICSzz). The double aromaticity considered results from two mutually orthogonal Hueckel p AO frameworks in a single mol. The familiar pi orbitals are augmented by the in-plane delocalization of electrons occupying sets of radial (rad) p orbitals. Such double aromaticity is present in B3-, C6H3+, C64+, C4B44+, C6, C5B2, C4B4, C2B8, B102-, B12, C10, C9B2, C8B4, C7B6, C6B8, and C14. Monocyclic C8 and C12 are doubly antiarom., as both the orthogonal pi and radial Hueckel sets are paratropic. Planar C7 and C9 monocycles have mixed arom. (pi) and anti-arom. (radial) systems. [on SciFinder (R)]

Details

Actions