Multi-Pulse Excitation Reveals a Novel Excited State Pathway in a Peryleneimide-Pentaphenylene Dyad

摘要

The excited state properties of a peryleneimide-pentaphenylene dyad were investigated in detail using pump-probe,single photon timing and three-beam pulsed experiments.Upon excitation with 395 nm pulses ultrafast energy transfer was found to occur from the pentaphenylene to the perylene subunit.In polar solvents this excitation energy transfer is followed by charge transfer from the electron donor pentaphenylene to the electron acceptor perylene.A three-beam femtosecond transient absorption technique revealed the relaxation dynamics of a higher lying singlet state of the peryleneimide subunit to occur on a picoseconds time scale.These results demonstrate the potential use of the three-beam femtosecond technique in manipulating excited states processes.