Vibrational Analysis of the Reduced Form of Polyaniline

The reduced form of polyaniline in the base form, the leucoemeraldine base, has been the subject of extensive studies these last years by means of many different techniques. Among them, Resonant Raman Scattering (RRS) has proved to be a powerful tool to investigate the vibrational properties of this polymer. In order to elucidate the nature of the vibrations in this compound, we have started calculations in different model compounds including aniline, diphenylamine, NjN’-d’iphenyl-l-phenylenedi amine as well as leucoemeraldine. A good fit is obtained for all the Raman and I.R. spectra of the studied compounds leading to a good assignment of the experimental Raman bands at 1181, 1219 and 1618 cm- 1. Calculations are in rather good agreement with previous assignments. Further work is in progress in order to give a clear interpretation of vibrational modes observed in other polyaniline forms, namelyemeraldine and pernigraniline.