IR response of poly(o-toluidine): Spectral modifications upon redox state change

The IR spectra of poly(o-toluidine) in the reduced, half and fully oxidized states have been studied in both salt and base forms. The bands in the range 1500 to 1600 cm(-1) undergo important intensity changes as the degree of oxidation increases. The IR spectra show that during the electrochemical polymerization there is an influence of the nature of the anion present in the electrolyte. This shows up as conformational differences in the polymer backbone, but it does not affect the chemical structure. Also, spectral changes are observed when the polymer is oxidized in supporting electrolytes containing different anions. This has been interpreted by considering that the less hydrated anions can approach closer to the positive centres of the protonated amine groups.