title: Radical cation and dication of fluorene fully annelated with bicyclo[2.2.2]octene units: importance of the quinoidal resonance structure in the cationic fluorene.
abstract: Fluorene 1 fully annelated with bicyclo[2.2.2]octene units was newly synthesized and oxidized to stable cationic species. The structure of radical cation salt 1(.+)SbCl(6)(-) was determined by X-ray crystallography, while the first fluorene dication 1(2+) was characterized by (1)H and (13)C NMR at -80 degrees C. Combined with the results of theoretical calculations, an important contribution of a quinoidal structure to the resonance hybrid was demonstrated in both 1(.+) and 1(2+). [structure: see text]
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Nishinaga
authors.forename: Ryota
authors.initials: R
authors.lastname: Inoue
authors.forename: Akira
authors.initials: A
authors.lastname: Matsuura
authors.forename: Koichi
authors.initials: K
authors.lastname: Komatsu