title: Singlet-singlet annihilation leading to a charge-transfer intermediate in chromophore-end-capped pentaphenylenes.
abstract: The excited-state properties of two peryleneimide chromophore end-capped pentaphenylene compounds were investigated in detail using femtosecond transient absorption and single-photon timing experiments. Singlet-singlet annihilation was found to promote one chromophore into a higher excited state and results in the formation of an ultra-short-living intermediate charge-transfer (CT) state in the S(n)-S(1) deactivation pathway. In low-polarity solvents, this CT state is found to be energetically higher than the first excited state and thus cannot be populated via one-photon excitation. The observed CT state decays with a time constant of about 1 ps to form the lowest singlet excited state. These results demonstrate the potential use of the singlet-singlet annihilation as a novel tool in studying reactions occurring in states that are energetically above the S(1).
authors.affiliation: Department of Chemistry, Katholieke Universiteit Leuven, Belgium.
authors.forename: Eduard
authors.initials: E
authors.lastname: Fron
authors.forename: Gerd
authors.initials: G
authors.lastname: Schweitzer
authors.forename: Josemon
authors.initials: J
authors.lastname: Jacob
authors.forename: Antoine
authors.initials: A
authors.lastname: Van Vooren
authors.forename: David
authors.initials: D
authors.lastname: Beljonne
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.forename: Mark
authors.initials: M
authors.lastname: Van der Auweraer
authors.forename: Frans C
authors.initials: FC
authors.lastname: De Schryver