title: Mixed-valence state of optically active 1',1'"-bis(2-phenylbutyl)-1,1''-biferrocenium pentaiodide: effects of cation symmetry and intermolecular interaction on trapped-/detrapped-valence states.
abstract: The effects of cation symmetry and packing on the mixed-valence state of binuclear ferrocene derivatives are discussed separately by using chiral isomers and racemic modification of 1',1' "-bis(2-phenylbutyl)-1,1' '-biferrocenium pentaiodide. The pentaiodide anion has a polymeric structure and is composed of triiodide anion and iodine molecule units. The (R,S) isomer having an inversion center shows a detrapped-valence state even at 78 K. On the other hand, the (R,R) and the (S,S) isomers having no inversion center show a trapped-valence state at room temperature. The racemic modification, however, consisting of the (R,R) and the (S,S) isomers shows a perfect detrapped-valence state at room temperature. This finding shows that the packing effect overcomes the effect of cation asymmetry.
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Oda
authors.forename: Satoru
authors.initials: S
authors.lastname: Nakashima
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Okuda