Structural and electronic transitions in poly(phenylenesulfide phenyleneamine) (PPSA) upon electrochemical doping have been investigated. The results indicate that polarons are the predominant charge defects at low doping levels, yielding an electronically and mechanically stable material, The electrochemical doping at high potentials induces a transition of the polarons to a bipolaron state. Due to the heterogeneous nature of the polymer chain and different oxidation potentials associated with aniline and phenylene sulfide units, the formation of polaron and bipolaron is distinguished as two separated steps. The dopant perchlorate ion exists in the polymer matrix, not only as charge neutralizer but also as a ligand that is simultaneously Coulombically bound to the positively charged S or N sites on one polymer chain and hydrogen bonded to the N-H group on the neighboring chain. The formation of such perchlorate anion centered Coulombic/hydrogen-bonded complexes has a major impact on the electrochemical activity and the morphology of the doped polymer. Also due to stabilization of the dopant ions, the doped polymer can be retained in a stable and desirable oxidation state.