Morphologically well-defined rods approximately one centimetre in length are effectively and economically obtained by mixing ortho-phenylenediamine oPD (30mM) with ammonium persulfate (APS) (12.5 mM) in an acidic solution (0.37 M HCl) at room temperature with and without the presence of 50 mM aniline. These, self-assembled, morphologically uniform products can be potentially scaled-up and used as morphological templates to fabricate well-defined structures of other materials such as conducting polymers.The products were characterized by Raman, UV-Vis, high-resolution NMR ( 1 H and 13 C), XRD, scanning electron microscopy (SEM), MS (mass spectrometry) and elemental analysis.Apart from certain differences in a visual appearance and in XRD diffractograms, other analytical data suggest that there were no structural changes upon addition of aniline into a reaction mixture. NMR and MS spectra imply that all syntheses carried out either with or without aniline resulted in a mixture of two products, attributed to 2,3-phenazinediamine and 3-aminophenazin-2-ol. A formation mechanism based on hydrogen bonding and π-π stacking has been proposed.