Femtosecond Photoelectron Imaging of Aligned Polyanions: Probing Molecular Dynamics through the Electron-Anion Coulomb Repulsion.
The first time-resolved photoelectron imaging study of a polyanion is presented. Using the alignment induced through resonance excitation, the photoelectron angular distributions can be qualitatively understood in terms of the position of localized excess charges on the molecular skeleton, which influence the photoemission dynamics. Pump-probe experiments are used to demonstrate that the photoelectron angular distribution is also sensitive to molecular dynamics. This is shown here for the rotational dynamics of a polyanion, in which the photoelectron anisotropy tracks the rotational coherence as it dephases. The methodology can in principle be applied to general molecular dynamics in large polyanions, providing a new route to studying ultrafast structural dynamics in complex gas-phase systems.
Department of Chemistry, University of Durham, DH1 3LE Durham, United Kingdom.
Daniel A
DA
Horke
Department of Chemistry, University of Durham, DH1 3LE Durham, United Kingdom.
Adam S
AS
Chatterley
Department of Chemistry, University of Durham, DH1 3LE Durham, United Kingdom.
Jan R R
JR
Verlet
alignment; multiply charged anions; photoelectron angular distribution; polyanions; repulsive coulomb barrier; time-resolved photoelectron spectroscopy; velocity map imaging