Liquid–Gas Interface of Iron Aqueous Solutions and Fenton Reagents
Iron ions have been a key ingredient in prebiotic chemical pathways at the origin of life on Earth as, for example, in prebiotic RNA catalyzed reactions (paper).
For these reasons, iron atoms remain present in many biomolecules of current living organism.
Dr. Ivan Gladich - ECLT fellow, Dr. Luca Artiglia and the surface chemistry group at Paul Scherrer Institute (Switzerland Zurich) have recently presented a joint computational and experimental work on the solvation and reactivity of Fe2+ and Fe3+ ions in aqueous solutions. By combing molecular dynamics simulation and in situ X-ray photoelectron spectroscopy they observed that both Fe2+ and Fe3+ ions are homogeneously distributed in solutions and exhibit a high spin octahedral coordination to water molecules, which is slightly distorted in the case of Fe2+. No indications of differences in the reaction mechanism between the liquid–vapor interface and the bulk of the solutions have been found, suggesting that Fe3+ and hydroxyl radicals are the only intermediates detectable by means of XPS. The outcomes of this work contribute to our current understanding of Fenton chemistry, i.e., the reaction between Fe2+ and hydrogen peroxide currently used in the mineralization of extremely stable molecule, while suggesting possible iron-driven chemical pathways at the origin of life on Earth.
This work has been published on The Journal of Physical Chemistry Letters, read the paper here.