In order to combine capacitive properties with processability, e.g. solubility in organic solvents, poly(3,4-propylenedioxythiophene) derivatives containing different functional groups like oxyphenyl methanol (-OPhCH2OH), oxybenzyl (-OBz), bromide (-Br) and tosyl (-OTs) were synthesized and electropolymerized as thin films from acetonitrile (ACN) using Et4NBF4 as an electrolyte. Multifunctionality in the substitution pattern of the polymer exhibits a similar trend between monomer oxidation potentials and specific capacitance (C-sp) vs. crystal size. The presence of pi-pi stacking interactions in the polymer structures plays an important role in building the crystal structures. The same order of flat band potential and C-sp values are observed for -OBz < -Br < -OTs < -OPhCH2OH substitutions. The structures of PProDOT-OBz and PProDOT-OPhCH2OH resemble each other much more than those of PProDOT-Br and PProDOT-OTs. Impedance measurements were conducted at different applied biases in order to define a Mott-Schottky analysis revealing the dependence of the semiconducting properties on the type of substituent present in the PProDOT derivative.