Aqueous Chemistry of Transition Metals in Oxidation State (I) in Nanodroplets

“Nanodroplets” consisting of a central ion surrounded by a solvation shell of water molecules provide an interesting medium for studies of aqueous transition‐metal chemistry in the unusual oxidation state (I). While VI undergoes efficient, solvent shell dependent redox reactions to VII and VIII, the absence of any similar reactivity in aqueous CrI, MnI, FeI, CoI, NiI, and CuI clusters is explained by a rapid precipitation of the corresponding single monochloride molecules from the nanosolutions. Aqueous chemistry of monovalent transition metal ions is studied in nanometer size droplets of water (see diagram). Recently observed redox and precipitation reactions on the single‐ion level are the first steps into a new area of transition‐metal chemistry.