Time-Resolved Photodetachment Anisotropy: Gas-Phase Rotational and Vibrational Dynamics of the Fluorescein Anion.
The photoelectron signal of the singly deprotonated fluorescein anion is found to be highly dependent on the relative polarization between pump and probe pulses, and time-resolved photodetachment anisotropy (TR-PA) is developed as a probe of the rotational dynamics of the chromophore. The total photoelectron signal shows both rotational and vibrational wavepacket dynamics, and we demonstrate how TR-PA can readily disentangle these dynamical processes. TR-PA in fluorescein presents specific opportunities for its development as a probe for rotational dynamics in large biomolecules as fluorescein derivatives are commonly incorporated in complex biomolecules and have been used extensively in time-resolved fluorescence anisotropy measurements, to which TR-PA is a gas-phase analogue.
†Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607 Hamburg, Germany.
Daniel A
DA
Horke
‡Ultrafast X-ray Science Laboratory, Cyclotron Road, Berkeley, California 94720, United States.
Adam S
AS
Chatterley
§Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, United Kingdom.
James N
JN
Bull
§Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, United Kingdom.
Jan R R
JR
Verlet
anisotropy; electron detachment; fluorescein; gas-phase anions; photoelectron spectroscopy; rotational anisotropy; ultrafast dynamics; wavepacket dynamics