München 2004 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MO: Molekülphysik
MO 4: Femtosekundenspektroskopie: Elektrontransfer
MO 4.3: Vortrag
Montag, 22. März 2004, 11:30–11:45, HS 315
Time-resolved spectroscopy of intramolecular excited state electron transfer — •Thomas Schultz1,2, Susanne Ullrich1, Stefan Lochbrunner1,3, and Albert Stolow1 — 1Steacie Institute for Molecular Sciences, National Research Council, Ottawa, Canada — 2Present address: Max-Born Institute for Non-linear Optics, Berlin, Germany — 3Present address: LS für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität München, Germany
We used time-resolved photoelectron spectroscopy to investigate the excited state electron transfer dynamics in a series of aminobenzonitriles including cyanobenzene, 4-aminobenzonitrile, N,N-4-dimethylaminobenzonitrile and N,N-4-diisopropylaminobenzonitrile (DIABN). This class of molecules has been extensively discussed as prototype models for twisted intramolecular charge transfer (TICT). We found very fast initial dynamics due to intramolecular vibrational energy redistribution in all investigated compounds. In DIABN we additionally observed population transfer from a locally excited to the charge transfer state. The electron transfer rate of 0.25/ps was independent of the excitation energy in the wavelength range 250 - 303 nm. A discrepancy between the observed population decay in the locally excited state and the population rise in the charge transfer signal. Possible explanations for this finding will be discussed in detail.