Chiral conducting surfaces based on the electropolymerization of 3,4-ethylenedioxythiophene

The synthesis and electrochemical characterization of d- and l-proline functionalized monothiophenes are reported. Both monomers 2L and 2D showed anodic peak potentials of 1.86 V vs. Fc+/Fc and their electropolymerization affords polymers that exhibit poor stability on platinum electrodes. However, the electrochemical copolymerization using cyclic voltammetry of 2L or 2D in the presence of EDOT gives polymeric films at the surface of the electrode with specific chirality. The E1/2 of the copolymers was found to be 0.38 V vs. Fc+/Fc. The copolymers display excellent electrochemical stability and adhesion properties on the surface of platinum and ITO electrodes. Moreover, the films also undergo a reversible color change between their doped (blue-green) and undoped (blue-brown) states. Incorporation of the chiral pendant group was confirmed through the appearance of characteristic CO stretching absorptions in the IR spectra of the copolymers.