title: Elongation of lifetime of the charge-separated state of ferrocene-naphthalenediimide-[60]fullerene triad via stepwise electron transfer.
abstract: Photoinduced electron-transfer processes of a newly synthesized rodlike covalently linked ferrocene-naphthalenediimide-[60]fullerene (Fc-NDI-C(60)) triad in which Fc is an electron donor and NDI and C(60) are electron acceptors with similar first one-electron reduction potentials have been studied in benzonitrile. In the examined Fc-NDI-C(60) triad, NDI with high molar absorptivity is considered to be the chromophore unit for photoexcitation. Although the free-energy calculations verify that photoinduced charge-separation processes via singlet- and triplet-excited states of NDI are feasible, transient absorption spectra observed upon femtosecond laser excitation of NDI at 390 nm revealed fast and efficient electron transfer from Fc to the singlet-excited state of NDI ((1)NDI*) to produce Fc(+)-NDI(•-)-C(60). Interestingly, this initial charge-separated state is followed by a stepwise electron transfer yielding Fc(+)-NDI-C(60)(•-). As a result of this sequential electron-transfer process, the lifetime of the charge-separated state (τ(CS)) is elongated to 935 ps, while Fc(+)-NDI(•-) has a lifetime of only 11 ps.
authors: Department of Material and Life Science, Graduate School of Engineering, Osaka University, ALCA, Japan Science and Technology Agency (JST), Suita, Osaka, Japan.
authors: Mustafa
authors: M
authors: Supur
authors: Mohamed E
authors: ME
authors: El-Khouly
authors: Jai Han
authors: JH
authors: Seok
authors: Kwang-Yol
authors: KY
authors: Kay
authors: Shunichi
authors: S
authors: Fukuzumi
mesh_terms: D004579:Electron Transport; D004583:Electrons; D004735:Energy Transfer; D005296:Ferrous Compounds / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D007094:Imides / Q000737:chemistry*; D007834:Lasers; D009682:Magnetic Resonance Spectroscopy; D000075163:Metallocenes; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D005296:Ferrous Compounds; D037741:Fullerenes; D007094:Imides; D000075163:Metallocenes; D009281:Naphthalenes; D009570:Nitriles; C542131:naphthalenediimide; C014356:benzonitrile; C069837:fullerene C60; C004998:ferrocene