Publié in Henry Rzepa's Blog

The transient π-complex formed during the “[5,5]” sigmatropic rearrangement of protonated N,O-diphenyl hydroxylamine can be (formally) represented as below, namely the interaction of a six-π-electron aromatic ring (the phenoxide anion 2 ) with a four-π-electron phenyl dication-anion pair 1 . Can one analyse this interaction in terms of aromaticity?