title: Photoinduced electron transfer in a rigid first generation triphenylamine core dendrimer substituted with a peryleneimide acceptor.
abstract: The electron-transfer process of a first generation dendrimer with a triphenylamine core substituted with one peryleneimide chromophore at the rim (N1P1) was investigated by steady-state and time-resolved spectroscopic techniques in two different solvents of medium and low polarity. Single photon counting experiments showed a fast charge separation and a thermally activated back reaction, which is uncommon for a polyaryl bridge or long-distance through-space electron transfer. The four exponential fluorescence decay can be traced to the presence of two subsets of molecules, which are constitutional isomers of N1P1. Although formally N1P1 resembles a donor-bridge-acceptor compound, detailed analysis of the data shows that the electron transfer occurs by a through-space mechanism. This amine core dendrimer has peculiar and unique characteristics resulting in the observation of efficient back transfer and delayed peryleneimide fluorescence in diethyl ether at 293 K and very long-lived charge recombination luminescence at 77 K.
authors.affiliation: Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Lor
authors.forename: Jan
authors.initials: J
authors.lastname: Thielemans
authors.forename: Lucien
authors.initials: L
authors.lastname: Viaene
authors.forename: Mircea
authors.initials: M
authors.lastname: Cotlet
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.forename: Tanja
authors.initials: T
authors.lastname: Weil
authors.forename: Christine
authors.initials: C
authors.lastname: Hampel
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Jan W
authors.initials: JW
authors.lastname: Verhoeven
authors.forename: Mark
authors.initials: M
authors.lastname: Van Der Auweraer
authors.forename: Frans C
authors.initials: FC
authors.lastname: De Schryver