Interaction of the europium chloride and polyaniline: formation of a novel conductive complex

A novel polyaniline (PANI):EuCl3 complex has been prepared and its conductivity, electronic absorption and luminescent spectra were studied. Changes in electronic absorption spectra showed that the europium ions possess both oxidative and pseudoprotonation activity with respect to the polymer chains in solution and solid films, respectively. Photoluminescence (PL) spectra showed that the charge transfer from the polymer to Eu3+ ions occurs and that there are two types of europium luminescent centers in the disordered polymer matrix. Electrical conductivity of the composite films with a stoichiometric ratio of PANI to the europium salt was found to be unexpectedly high and comparable with that of the protonic acid doped PANI. Mechanisms of the PANI:EuCl3 complex formation are discussed.