Electron Solvation in Finite Systems: Femtosecond Dynamics of Iodide·(Water)n Anion Clusters
L. Lehr,
*
M. T. Zanni,
*
C. Frischkorn,
R. Weinkauf,
D. M. Neumark
Electron solvation dynamics in photoexcited anion clusters of
I
(D2O)n=4-6 and
I(H2O)4-6 were probed by using
femtosecond photoelectron spectroscopy (FPES). An ultrafast pump pulse
excited the anion to the cluster analog of the
charge-transfer-to-solvent state seen for I in aqueous
solution. Evolution of this state was monitored by time-resolved
photoelectron spectroscopy using an ultrafast probe pulse. The excited
n = 4 clusters showed simple population decay, but in
the n = 5 and 6 clusters the solvent molecules
rearranged to stabilize and localize the excess electron, showing
characteristics associated with electron solvation dynamics in bulk
water. Comparison of the FPES of
I(D2O)n with
I(H2O)n indicates more
rapid solvation in the H2O clusters.
Department of Chemistry, University of California, Berkeley, CA
94720, USA and Chemical Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, CA 94720, USA.
*
These authors contributed equally to this work.
Permanent address: Institut für
Physikalische und Theoretische Chemie, Technischen Universität
München, D-85748 Garching, Germany.
To whom correspondence should be addressed. E-mail:
dan{at}radon.cchem.berkeley.edu
