title: Triradical cation of p-phenylenediamine having two nitroxide radical groups: spin alignment mediated by delocalized spin.
abstract: The cationic state of a p-phenylenediamine (PDA) molecule having two nitroxide radical groups was prepared and characterized using electrochemical, electron spin resonance (ESR) spectroscopic, and absorption spectroscopic methods. The delocalized intervalence state of the p-phenylendiamine (PDA) moiety was detected in the cationic state. From the pulsed ESR measurements, it was confirmed that the delocalized spin induces parallel spin alignment between the localized two nitroxide groups which are magnetically weakly coupled in the neutral state. It was found that the resulting high-spin alignment does not seriously affect the delocalized intervalence state of the PDA radical cation.
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. aito@sci.kyoto-u.ac.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ito
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nakano
authors.forename: Masashi
authors.initials: M
authors.lastname: Urabe
authors.forename: Tatsuhisa
authors.initials: T
authors.lastname: Kato
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Tanaka