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.