Air oxidation of [Fe(II)L](ClO4)(2) and [Co(II)L](ClO4)(2) in acetonitrile in the presence of NEt(3) affords deep blue and red microcrystals of [Fe-III(L-3H)] and [Co-III(L-3H)], respectively (L = 1,4,7-tris(o-aminobenzyl)-1,4,7-triazacyclononane, and L-3H is its triply deprotonated trianion). The reaction of L with "manganese(III) acetate" in ethanol in the presence of air yields a deep blue solution from which, upon addition of Na[BPh(4)], dark blue crystals of [Mn-IV(L-3H)]BPh(4) were obtained. The same material was obtained from air oxidation of an CH3CN solution of [Mn(II)L](ClO4)(2) to which NEt(3) and NaBPh(4) had been added. The crystal structure of the manganese(IV) complex has been determined try single-crystal X-ray crystallography. [Mn-IV(L-3H)]BPh(4) crystallizes in the orthorhombic space group Pbca with Z = 8, a = 19.700(9) Angstrom, b = 20.255(7) Angstrom, and c = 21.092(5) Angstrom. The manganese(IV) ion is in a distorted octahedral environment of three facially coordinated tertiary nitrogen donor atoms and three anilide nitrogen donors. The cation possesses idealized C-3 symmetry.