Spectroelectrochemical study of the redox reactions of polyazulene on aluminum substrates

Polyazulene (PAz) films have been electrochemically synthesized on aluminum substrates. Both p- and n-doping of the formed PAz films have been studied on Al and Pt substrates with cyclic voltammetry (CV), in situ FTIR with Attenuated Total Reflectance mode (FTIR–ATR), and in situ UV–vis. During p-doping on both substrates the IR spectra show an appearance of infrared active vibration bands (IRAV) in the wavenumber region 1600–800 cm−1. The IRAV bands increase with increased charging level and appear at the similar wavenumbers regardless of the substrate. In the case of n-doping the spectroelectrochemical response was dependent on the substrate. PAz on Pt showed a reversible n-doping behavior, this could be confirmed with in situ FTIR–ATR and in situ UV–vis. PAz on Al did not show a reversible n-doping although the film did undergo certain potential induced structural changes during reduction.