X-ray photoelectron spectroscopic studies of conductive polypyrrole complexes chemically synthesized withFeCl3

Highly conductive polypyrrole complexes obtained from chemical polymerization and oxidation of pyrrole by ${\mathrm{FeCl}}_3$ were studied by x-ray photoelectron spectroscopy. Properly deconvoluted Cl 2p core-level spectra of the complexes suggest that the chlorine dopant can exist in three chemical states. Thus reaction stoichiometries based on the total chlorine balance of the complex can be quite misleading. From the actual chloride-anion content of the complexes and the corresponding amount of deprotonated pyrrolylium nitrogens after base ‘‘compensation,’’ a reaction stoichiometry corresponding to 25% oxidized pyrrole units in the complex is favored.