Are antiaromatic rings stacked face-to-face aromatic?
The stacking of 4n pi electron hydrocarbon rings into superphane structures can eliminate their antiaromaticity and result in through-space three-dimensional aromatic character. This is demonstrated by the bond length equalized geometries and diatropic NICS values of the methano-bridged superphane series with interacting three- to nine-membered 4n pi electron rings. Along with triplet and Möbius strategies, stacking is the third way to achieve aromatic ring systems with 4n pi electrons.
Corminboeuf
Clémence
C
Department of Chemistry and Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602, USA.
Schleyer
Paul von Ragué
Pv
Warner
Philip
P