Aminyl radicals may one day be useful oxidn. catalysts if their thermodn. instability can be overcome, for example, through complexation with a metal. Deprotonation of the semiquinonato-anilido complex [RuIII(NHPh-bpa)(tBu2sq)]+ (1; NHPh-bpa = 2-(bis(pyridylmethyl)aminomethyl)-anilido ligand; tBu2sq- = 3,5-di-tert-butylsemiquinonate) leads to formation of the semiquinonato-anilino-radical complex [RuII(·NPh-bpa)(tBu2sq)] (2). Electrochem. redn. of 2 leads to formation of the catecholato-anilino radical complex [RuII(·NPh-bpa)(tBu2cat)]- (3). Treatment of 1 with MeSO3H gave the semiquinone-aniline complex [RuIII(NH2Ph-bpa)(tBu2sq)]2+ (4). The complexes were studied using cyclic voltammetry, EPR, magnetic susceptibility and DFT calcns.