Direct observation of the collapse of the delocalized excess electron in water

0432523 - ÚOCHB 2015 RIV GB eng J - Journal Article
Savolainen, J. - Uhlig, Frank - Ahmed, S. - Hamm, P. - Jungwirth, Pavel
Direct observation of the collapse of the delocalized excess electron in water.
Nature Chemistry. Roč. 6, č. 8 (2014), s. 697-701. ISSN 1755-4330. E-ISSN 1755-4349
R&D Projects: GA ČR GBP208/12/G016
Institutional support: RVO:61388963
Keywords : hydrated electron * THz spectroscopy * ab initio molecular dynamics
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 25.325, year: 2014

It is generally assumed that the hydrated electron occupies a quasi-spherical cavity surrounded by only a few water molecules in its equilibrated state. However, in the very moment of its generation, before water has had time to respond to the extra charge, it is expected to be significantly larger in size. According to a particle-in-a-box picture, the frequency of its absorption spectrum is a sensitive measure of the initial size of the electronic wavefunction. Here, using transient terahertz spectroscopy, we show that the excess electron initially absorbs in the far-infrared at a frequency for which accompanying ab initio molecular dynamics simulations estimate an initial delocalization length of approximate to 40 angstrom. The electron subsequently shrinks due to solvation and thereby leaves the terahertz observation window very quickly, within approximate to 200 fs.
Permanent Link: http://hdl.handle.net/11104/0236876