Abstract
Neutron scattering data are presented for electrically conducting films of polypyrrole prepared electrochemically using toluene sulphonate as the dopant. These data show unambiguously that these films possess an anisotropic molecular structure, in which the planes of the aromatic rings of the polypyrrole chain lie preferentially parallel to the sample surface and hence to the growth face of the electrode. The dopant molecules also adopt this anisotropy but lie between the polypyrrole layers.