title: The Bingel monoadducts of La@C82: synthesis, characterization, and electrochemistry.
abstract: The reaction of La@C82 with diethyl bromomalonate in the presence of base (the Bingel reaction) generated five monoadducts which have been fully characterized. It was found that four of them (mono-A, -B, -C, and -D) are ESR-inactive, suggesting singly bonded regioisomers. In contrast, the fifth product (mono-E) is ESR-active, indicating that it possesses a cyclic moiety between the appended malonate group and the fullerene cage, analogous to conventional Bingel adducts. The differences in the molecular structures of mono-A, -B, -C, and -E result in varying thermal stabilities and electrochemical behavior. In particular, the singly bonded monoadducts undergo the retro-Bingel reaction either under thermal treatment or during electron transfer on the cyclic voltammetric timescale. However, mono-E shows remarkable thermal stability and perfect reversibility under the same experimental conditions.
authors.affiliation: Center for Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Lai
authors.initials: L
authors.lastname: Feng
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Wakahara
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Nakahodo
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Qiuyue
authors.initials: Q
authors.lastname: Piao
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Maeda
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Lian
authors.forename: Takeshi
authors.initials: T
authors.lastname: Akasaka
authors.forename: Ernst
authors.initials: E
authors.lastname: Horn
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoza
authors.forename: Tatsuhisa
authors.initials: T
authors.lastname: Kato
authors.forename: Naomi
authors.initials: N
authors.lastname: Mizorogi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase