RECENT ADVANCES IN THE PHYSICAL AND SPECTROSCOPIC PROPERTIES OF POLYPYRROLE FILMS, PARTICULARLY THOSE CONTAINING TRANSITION-METAL COMPLEXES AS COUNTERANIONS

The results of recent investigations of polypyrrole (PPy) films using a variety of physical and spectroscopic techniques are reviewed. The physical techniques discussed include conductivity and X-ray diffraction measurements; the spectroscopic techniques reviewed comprise optical, electron paramagnetic resonance (EPR), and Mossbauer spectroscopies. After consideration of the historical background, applications, and the growth mechanism of PPy, a review of the nature of the charge carriers and the structure is presented. The data reported for a subclass of PPy films containing transition-metal complexes as counteranions are given special emphasis.