Catalytic oxidation of hydroxyurea to bound NO+/NO2- mediated by pentacyano(L)ferrates. Characterization of the nitroxide radical, bound C-nitrosoformamide and NO as reaction intermediates

► We studied the oxidation of hydroxyurea by [Fe(CN)5H2O]2− in aqueous solutions. ► C-nitrosoformamide coordinated to [FeII(CN)5]3− was obtained and characterized. ► Metal catalyzed oxidation of hydroxyurea forms N-containing species from −1 to +3.