title: Synthesis, properties, and redox behavior of tetracyanobutadiene and dicyanoquinodimethane chromophores bearing two azulenyl substituents.
abstract: Acetylene derivatives with an azulenyl group at both terminals have been prepared by palladium-catalyzed alkynylation under Sonogashira-Hagihara conditions. These alkynes reacted with tetracyanoethylene and 7,7,8,8-tetracyanoquinodimethane in a formal [2 + 2] cycloaddition-retroelectrocyclization reaction to afford the corresponding new tetracyanobutadienes (TCBDs) and dicyanoquinodimethanes (DCNQs), respectively, in excellent yields. Intramolecular CT absorption bands were found in the UV-vis spectra of the novel chromophores, and CV and DPV showed that they exhibited a reversible two-stage reduction wave, due to the electrochemical reduction of TCBD and DCNQ moieties. Color changes were also observed during the electrochemical reduction.
authors.affiliation: Department of Chemistry, Faculty School of Science, Shinshu University , Matsumoto 390-8621, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Shoji
authors.forename: Mitsuhisa
authors.initials: M
authors.lastname: Maruyama
authors.forename: Erika
authors.initials: E
authors.lastname: Shimomura
authors.forename: Akifumi
authors.initials: A
authors.lastname: Maruyama
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
authors.forename: Noboru
authors.initials: N
authors.lastname: Morita