THE 2-DIMENSIONAL STRUCTURE OF POLYPYRROLE FILMS

An analysis of the XPS core level spectra of polypyrrole films provide s evidence that a two-dimensional microscopic structure can be obtaine d when high current densities are applied during the electropolymeriza tion process. The properties of such films are compared to those of pr edominantly one-dimensional polypyrrole films prepared at low current densities. The structural differences occurring in the N(1s) core leve l spectra are related to different partial charges at the nitrogen ato ms. These appear only in heterocyclic subunits which are based on 2-3 linked pyrrole monomers, as determined by semi-empirical MNDO calculat ions. The model calculations allow us to compose a structural model of two-dimensional polypyrrole which is in accordance with the elemental analysis of such films.