Solvent-mediated electron hopping: long-range charge transfer in IBr-(CO2) photodissociation.
Chemical bond breaking involves coupled electronic and nuclear dynamics that can take place on multiple electronic surfaces. Here we report a time-resolved experimental and theoretical investigation of nonadiabatic dynamics during photodissociation of a complex of iodine monobromide anion with carbon dioxide [IBr-(CO2)] on the second excited (A') electronic state. Previous experimental work showed that the dissociation of bare IBr- yields only I- + Br products. However, in IBr-(CO2), time-resolved photoelectron spectroscopy reveals that a subset of the dissociating molecules undergoes an electron transfer from iodine to bromine 350 femtoseconds after the initial excitation. Ab initio calculations and molecular dynamics simulations elucidate the mechanism for this charge hop and highlight the crucial role of the carbon dioxide molecule. The charge transfer between two recoiling atoms, assisted by a single solvent-like molecule, provides a notable limiting case of solvent-driven electron transfer over a distance of 7 angstroms.
Sheps
Leonid
L
JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA.
Miller
Elisa M
EM
Horvath
Samantha
S
Thompson
Matthew A
MA
Parson
Robert
R
McCoy
Anne B
AB
Lineberger
W Carl
WC