Polyaniline, which is soluble in common organic solvents, has been synthesized through the oxidative chemical polymerization of aniline in the presence of benzene diazonium chloride salt in an aqueous HCl acid medium. The blue-black polyaniline thus prepared exists in a lower oxidation state than emeraldine. An X-ray photoelectron spectroscopy study has shown that the intrinsic oxidation state of the polymer is 0.38. An elemental analysis has shown that the fractional doping level or degree of oxidation of the blue-black polyaniline is 0.26. The product is believed to consist of a lower number of imine nitrogens in comparison with the polyemeraldine base. This fact is also corroborated by the lower electrical conductivity of the polymer. (c) 2007 Wiley Periodicals, Inc.