The spectroscopic characterization of polydiphenylamine and one of its oligomeric fractions

Polydiphenylamine (PDPA), electrochemically synthesized by a potentiodynamic method, was characterized by UV-vis absorption, Raman, and infrared spectroscopies. Depending on the potential applied, two types of adsorbed polymeric films were obtained on the electrode. A soluble oligomeric fraction formed in the electrolyte solution was also characterized. The Raman spectra of the polymeric film formed at more positive final potential and of the oligomeric fraction show the predominance of the diphenosemiquinoneimine structure. These results, along with the UV-vis and conductivity data, show that the band gap energy of the conducting polymer is dependent on the diphenosemiquinoneimine structure present in the polymer backbone. The IR spectra show some features that indicate interchain hydrogen bonding.