title: Effect of dual fullerenes on lifetimes of charge-separated States of subphthalocyanine-triphenylamine-fullerene molecular systems.
abstract: Photoinduced intramolecular electron-transfer events of the newly synthesized subphthalocyanine-triphenylamine-fullerene triad (SubPc-TPA-C60) and subphthalocyanine-triphenylamine-bisfullerene tetrad (SubPc-TPA-(C(60))(2)) were studied. The geometric and electronic structures of the triad were probed by ab initio B3LYP/3-21G method, which predicts SubPc-TPA(*+)-C(60)(*-) as a stable charge-separated state. The photoinduced events via the excited singlet state of SubPc were monitored by time-resolved emission measurements as well as transient absorption techniques. Efficient charge-separations via the excited states of SubPc were observed with the rates of approximately 10(10) s(-)1. Compared with the SubPc-TPA dyad, a long-lived charge-separated state was observed for the SubPc-TPA-C(60) triad with the lifetime of the radical ion pairs (tau(RIP)) of 670 ns in benzonitrile. Interestingly, further charge stabilization was achieved in the charge-separated state of SubPc-TPA-(C(60))(2), in which the tau(RIP) was found to be 1050 ns in benzonitrile.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Sendai, 980-8577 Japan.
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: El-Khouly
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Shim
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Araki
authors.forename: Osamu
authors.initials: O
authors.lastname: Ito
authors.forename: Kwang-Yol
authors.initials: KY
authors.lastname: Kay
mesh_terms: D004159:Diphenylamine / Q000031:analogs & derivatives* / Q000737:chemistry; D004563:Electrochemistry; D037741:Fullerenes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008956:Models, Chemical; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods
chemical_list: D037741:Fullerenes; D007211:Indoles; D054833:Isoindoles; D004159:Diphenylamine; C069837:fullerene C60; C013647:phthalocyanine