title: Inhibition of the formation and decay of stilbene core radical cations by the dendron during the photoinduced electron transfer.
abstract: Formation and decay processes of stilbene core radical cation (ST*+) during the photoinduced electron transfer have been studied for a series of stilbene bearing benzyl ether-type dendrons (D). ST*+ and the radical cation of peripheral dendron (D*+) were generated by intermolecular hole transfer from biphenyl radical cation, which was generated from photoinduced electron transfer from biphenyl to the singlet-excited 9,10-dicyanoanthracene in a mixture of acetonitrile and 1,2-dichloroethane (3:1). An intramolecular dimer radical cation of benzyl groups at the terminal of stilbene dendrimer was indicated as a hole trapping site. Subsequent hole transfer from the trapping site to the core ST generated ST*+. The shielding effects of D depending on the dendrimer generation on the growth and decay of ST*+ were observed. It was revealed for the first time that D acts as the hole trapping site and the hole conductor on the way of the exothermic hole transfer from the terminal of D to the central core ST. We also found that D inhibits the charge recombination with 9,10-dicyanoanthracene radical anion because of the steric hindrance.
authors.affiliation: The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Hara
authors.forename: Shingo
authors.initials: S
authors.lastname: Samori
authors.forename: Xichen
authors.initials: X
authors.lastname: Cai
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tojo
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Arai
authors.forename: Atsuya
authors.initials: A
authors.lastname: Momotake
authors.forename: Junpei
authors.initials: J
authors.lastname: Hayakawa
authors.forename: Mayuko
authors.initials: M
authors.lastname: Uda
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Kawai
authors.forename: Masayuki
authors.initials: M
authors.lastname: Endo
authors.forename: Mamoru
authors.initials: M
authors.lastname: Fujitsuka
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Majima