[en] The amino radical has been produced by reaction of the OH radical with ammonia in irradiated aqueous solutions. At pH 11.4 the unprotonated radical, NH₂, is produced with a rate constant k = (9 +- 1) x 10⁷ M^-1 s^-1, while in acidic solution the corresponding reaction of OH with NH₄⁺ is too slow to be observed. The SO₄^- and PO₄^2- radicals are found to react more slowly with NH₃ than does OH. It is concluded that these radicals react with ammonia by hydrogen abstraction and not by electron transfer oxidation. The method is not useful for the production of the protonated NH₃⁺ radical. The subsequent reactions of NH₂ are followed by monitoring the kinetics of formation of the more strongly absorbing radical products. Rate constants for the reactions of NH₂ with various substituted phenoxide ions have been measured; with phenoxide itself at pH > 11, k = 3.0 x 10⁶ M^-1 s^-1. These rate constants are strongly affected by the ring substituent. When the rates are plotted against the Hammett sigma values, a slope corresponding to rho approximately = -3.3 is derived. The mechanism is considered to be oxidation of the phenoxide ions by electron transfer. Although the NH₂ radical was found to be relatively unreactive toward addition to benzene, its adduct radical to the fumarate anion has been observed by ESR. The NH₂ radical may also be produced by reaction of e^-/sub aq/ with NH₂OH. An attempt was made to generate the NH₃⁺ radical in the corresponding reaction with the acid form of hydroxylamine, ⁺NH₃OH, which is especially fast. On the basis of several pieces of evidence, we postulate that NH₃⁺ cannot be the main product of this reaction but that ⁺NH₃OH splits preferentially into the OH radical and NH₃. 1 table, 1 figure