Synthesis of polyaniline by using CuCl2 as oxidizing agent

The reaction of aniline with copper(II) chloride in the presence of p-toluene sulfonic acid was investigated. The reactions were carried out in aqueous media for 24 h under a nitrogen atmosphere. The products obtained were characterized by FT-IR, UV–Vis XPS, SEM, N K-edge NEXAFS and CP MAS 13C NMR. Elemental analysis was also carried out to determine the elemental composition of the product. The results showed the presence of partially oxidized, partially protonated polyaniline with [CuCl3]− as the dopant counter ion. A decrease in the final pH and increase in the reaction yield was observed with an increase in the oxidant to monomer ratio. The increase in the yield is due to an increase in the oxidation potential of CuCl2 with an increase in its molar concentration. The low product yields achieved are attributed to the co-formation of a copper(II) chloride aniline coordination complex.