The electrochemical oxidations of pyrene, fluorene and their derivatives yield conducting polymers with electrical conductivities of 10-1 to 1 S/cm. Their elemental analysis data indicate oxidation levels of 0.06 to 0.31 per monomer unit. Substituents determine whether electropolymerization occurs, or soluble products are formed instead. The relative importance of these pathways is dependent on the stability of the intermediate radical cation, and these are discussed in light of INDO molecular orbital calculations. © 1985.