Double aromaticity in monocyclic carbon, boron, and borocarbon rings based on magnetic criteria

作者：Wodrich Matthew D; Corminboeuf Clemence; Park Sung Soo; Schleyer Paul von Rague^*

来源：Chemistry - A European Journal, 2007, 13(16): 4582-4593.

DOI：10.1002/chem.200700154

• aromaticity
• borocarbon
• carbon clusters
• density functional calculations
• magnetic properties

The double-aromatic character of selected monocyclic carbon, boron, and borocarbon rings is demonstrated by refined nucleus-independent chemical 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 Huckel p AO frameworks in a single molecule. The familiar a orbitals are augmented by the in-plane delocalization of electrons occupying sets of radial (rad) p orbitals. Such double aromaticity is present in B-3(-), C6H3+, C(6)(4+)6+, C4B44+, C-6, C5B2, C4B4, C2B8, B-10(2-), B-12, C-10, C9B2, C8B4, C7B6, C6B8, and C-14. Monocyclic C-8 and C-12 are doubly antiaromatic, as both the orthogonal pi and radial Huckel sets are paratropic. Planar C-7 and C-9 monocycles have mixed aromatic (a) and antiaromatic (radial) systems.

• 出版日期2007