title: Generation of long-lived radical ions through enhanced photoinduced electron transfer processes between [60]fullerene and phenothiazine derivatives.
abstract: Photoinduced electron transfer processes between fullerenes (C60) and four phenothiazine derivatives (PTZs) in the absence and presence of hexylviologen dication (HV2+) have been studied by the transient absorption method in the visible and near-IR regions. Electron-transfer takes place from PTZs to the triplet states of fullerenes (3C60*) giving the radical anion of fullerenes (C60.-) and the radical cations of PTZs (PTZ.+). The rate constants and efficiencies of electron transfer are quite high, because of the high electron-donor abilities of PTZs as elucidated by their low oxidation potentials. On addition of HV2+ to the C60 and PTZ systems, the electron-mediating process occurs from C60.- to HV2+, yielding the viologen radical cation (HV.+). In the presence of a sacrificial donor, HV.+ persisted for a long time.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Sendai 980-8577, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Araki
authors.forename: Osamu
authors.initials: O
authors.lastname: Ito
authors.forename: Maksudul M
authors.initials: MM
authors.lastname: Alam