title: Diprotonated [28]hexaphyrins(1.1.1.1.1.1): triangular antiaromatic macrocycles.
abstract: Protonation of meso-aryl [28]hexaphyrins(1.1.1.1.1.1) triggered conformational changes. Whereas protonation with trifluoroacetic acid led to the formation of monoprotonated Möbius aromatic species, protonation with methanesulfonic acid led to the formation of diprotonated triangular antiaromatic species. A peripherally hexaphenylated [28]hexaphyrin was rationally designed and prepared to undergo diprotonation to favorably afford a triangular-shaped antiaromatic species.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502 (Japan).
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Ishida
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Higashino
authors.forename: Shigeki
authors.initials: S
authors.lastname: Mori
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Mori
authors.forename: Naoki
authors.initials: N
authors.lastname: Aratani
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Lim
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Osuka
keywords: Möbius aromaticity; antiaromaticity; hexaphyrin; protonation; triangular shape