title: Bis(10-methylacridinium)s as a versatile platform for redox-active functionalized dyes and novel structures.
abstract: 10-Methylacridinium is a stable aromatic cation exhibiting yellow-orange color and strong green fluorescence (FL), and can be used as a versatile building block in constructing a wide variety of novel π-electron systems. The dications with the two chromophores connected by a proper π spacer undergo reversible "dyrex" (dynamic redox) behavior, and C-C bond formation/cleavage is accompanied by their redox reactions. The prototype is biphenyl-2,2'-diylbis(10-methylacridinium), which exhibits electrochromic response with ON/OFF switching of FL during the reversible interconversion with the di(spiroacridan)-type electron donor. Slight structural alteration under the concept of "MFMS" (maximum function on the minimum skeleton) endowed the dyrex system with metal-binding or chiroptical properties, which could be modified by the redox reactions. Some of the di(spiroacridan) derivatives generated from bis(10-methylacridinium)s have extreme structural parameters, such as the greatest C-C bond length ever reported.
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan. tak@sci.hokudai.ac.jp.
authors.forename: Takanori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Takeda
authors.forename: Eisuke
authors.initials: E
authors.lastname: Ohta
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Wada
authors.forename: Ryo
authors.initials: R
authors.lastname: Katoono
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kawai
authors.forename: Kenshu
authors.initials: K
authors.lastname: Fujiwara
keywords: cations; heterocycles; redox chemistry; steric hindrance; strained molecules