Report

Solvent-Mediated Electron Hopping: Long-Range Charge Transfer in IBr(CO2) Photodissociation

+ See all authors and affiliations

Science  09 Apr 2010:
Vol. 328, Issue 5975, pp. 220-224
DOI: 10.1126/science.1184616

You are currently viewing the abstract.

View Full Text

Abstract

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.

  • * Present address: NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.

View Full Text