Formation of 2,3-diaminophenazines and their self-assembly into nanobelts in aqueous medium

One-dimensional (1D) nanobelts of several hundred micrometers in length, several hundred nanometers in width and several hundred nanometers in height are obtained by direct mixing of ortho-phenylenediamine (oPD) and FeCl3 aqueous solution at room temperature. The nanobelts were characterized by elemental analysis, liquid chromatography/mass spectrometry (LC/MS), NMR (H-1 and C-13), FT-IR, UV-vis, thermogravimetric (TG) and conductivity measurement. The nanobelts are identified as 2,3-diaminophenazine assemblies. The formation of the nanobelts involves two stages: (1) oxidation of oPD by FeCl3, yielding individual 2,3-diaminophenazine molecules; and (2) self-assembly of the 2,3-diaminophenazine, forming the ID nanobelts. The nanobelts exhibit fairly high thermal stability and show conductivity at the level of semiconductors. (C) 2007 Elsevier Ltd. All rights reserved.