title: Synthesis, properties, and redox behavior of 1,1,4,4-tetracyano-2-ferrocenyl-1,3-butadienes connected by aryl, biaryl, and teraryl spacers.
abstract: Aryl-substituted 1,1,4,4-tetracyano-1,3-butadienes (FcTCBDs) and bis(1,1,4,4-tetracyanobutadiene)s (bis-FcTCBDs), possessing a ferrocenyl group on each terminal, were prepared by the reaction of a variety of alkynes with tetracyanoethylene (TCNE) in a [2+2] cycloaddition reaction, followed by retro-electrocyclization of the initially formed [2+2] cycloadducts (i.e., cyclobutene derivatives). The characteristic intramolecular charge transfer (ICT) between the donor (ferrocene) and acceptor (TCBD) moieties were investigated by using UV/Vis spectroscopy. The redox behaviors of FcTCBDs and bis-FcTCBDs were examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which revealed their properties of multi-electron transfer depending on the number of ferrocene and TCBD moieties. Moreover, significant color changes were observed by visible spectroscopy under the electrochemical reduction conditions.
authors.affiliation: Department of Chemistry, Faculty School of Science, Shinshu University, Matsumoto 390-8621, Nagano (Japan), Fax: (+) 81-263-37-2476; Department of Material Science, Graduate School of Science and Technology, Shinshu University, Matsumoto 390-8621, Nagano (Japan). tshoji@shinshu-u.ac.jp.
authors.forename: Taku
authors.initials: T
authors.lastname: Shoji
authors.forename: Akifumi
authors.initials: A
authors.lastname: Maruyama
authors.forename: Chisa
authors.initials: C
authors.lastname: Yaku
authors.forename: Natsumi
authors.initials: N
authors.lastname: Kamata
authors.forename: Shunji
authors.initials: S
authors.lastname: Ito
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Okujima
authors.forename: Kozo
authors.initials: K
authors.lastname: Toyota
keywords: chromophores; cycloaddition; donor-acceptor systems; ferrocene; redox chemistry