Chemical oxidative polymerization as a synthetic route to electrically conducting polypyrroles
Various transition metal compounds, specifically Fe (III) and Cu (II) complexes, are shown to function both as polymerization initiators and as dopants in converting pyrrole and substituted pyrroles into electrically conducting polymers. The resulting polypyrroles are produced as black powders having conductivities ranging from 10-6 to 102 ohm-1 cm-1 depending upon the specific reaction conditions. The FeCl3/pyrrole system is examined in some detail with respect to the critical reaction parameters which include reactant stoichiometry, temperature and the reaction medium. Mechanistic implications are discussed with respect to the role of a solvent-FeCl3pyrrole intermediate.