Simultaneous and Spontaneous Oxidation and Reduction in Microdroplets by the Water Radical Cation/Anion Pair

Microdroplets show unique chemistry, especially in their intrinsic redox properties, and to this we here add a case of simultaneous spontaneous oxidation reduction. We report the concurrent conversions several phosphonates phosphonic acids by reduction (R?P ? H?P) pentavalent phosphoric oxidation. The experimental results suggest that active reagent is water radical cation/anion pair. cation observed directly as ionized dimer while anion only seen indirectly though carbon dioxide formate. coexistence oxidative reductive species turn supports proposal double-layer structure at microdroplet surface, where are separated accumulated.