3,7-Diaminophenothiazine derivatives are readily synthesized via two-fold Buchwald–Hartwig coupling of 10-hexyl 3,7-dibromo-10H-phenothiazine with a series of primary and secondary anilines and amines. All derivatives possess two reversible oxidations at low potentials with remarkable semiquinone formation constants. The electronic structure of this novel class of phenothiazinyl-oligoanilines is additionally studied and rationalized by DFT computations and correlation studies between selected experimental and computational electronic data.