Crystalline phases of electrically conductive poly(p‐phenylene vinylene)

Poly(p‐phenylene vinylene) (PPV) undergoes a first‐order crystal‐crystal phase transition when chemically doped with AsF5, SbF5, or H2SO4 or electrochemically oxidized with ClO‐4 as the counterion. These structures have been observed using wide‐angle x‐ray diffraction. Doping with these agents does not disrupt the original orientation of the PPV crystallites. The crystalline phases obtained with all dopants employed here are similar in character, indicating a closely related family of electrically conductive structures having orthorhombic symmetry. An electrically conductive phase consisting of layers of polymer chains separated by a layer of the chemical dopant is proposed.