Ultrafast Chemistry of Water Radical Cation, H₂O^•+, in Aqueous Solutions

Oxidation reactions by radicals constitute a very important class of chemical reactions in solution. Radiation Chemistry methods allow producing, in a controlled way, very reactive oxidizing radicals, such as OH^•, CO₃^•-, NO₃^•, SO₄^•-, and N₃^•. Although the radical cation of water, H₂O^•+, with a very short lifetime (shorter than 1 ps) is the precursor of these radicals in aqueous solutions, its chemistry is usually known to be limited to the reaction of proton transfer by forming OH^• radical. Herein, we stress situations where H₂O^•+ undergoes electron transfer reaction in competition with proton transfer.