Ultrafast electron transfer and solvation dynamics in amorphous ice layers on Cu(111)

Abstract

The solvation dynamics of excess electrons in water has attracted special interest due to its fundamental importance for charge transfer and solvation processes in chemistry and biology and the apparent simplicity of the hydrated electron as a model solute [1-3]. Upon photoinjection in liquid water at room temperature an excess electron localizes and relaxes on a timescale of ~1 ps via several precursor states to the equilibrated solvated ground state [3]. So far, most studies have focused on the solvation dynamics in the liquid phase, but very little is known about the initial stages of electron trapping in supercooled water and ice [4]. Electrons in precursor states to solvated electrons in ice are known to giantly enhance the dissociation of chlorfluorocarbons (CFCs) adsorbed on ice surfaces, a reaction which is of high relevance in the depletion of the ozone layer by released Cl atoms [5]. Photoinduced electron transfer into amorphous ice films leads also to molecular rearrangements and crystallization [6].