The Synthesis, Properties and Structure of Poly(Peri-Naphthalene): a Conducting, Undoped Organic Polymer

The synthesis of ribbons of a highly conducting, undoped organic polymer by the pyrolysis of 3,4,9,10-perylene-tetracarboxylicdianhydride is described. The conductivity is not decreased upon exposure to selected donor or acceptor dopants, suggesting that the high observed conductivity is not due to a charge-transfer complex. Elemental analysis and infrared and Raman spectroscopies are consistent with structural assignment as poly (perj -naphthalene). PPN. However, observed diffraction patterns are not consistent with crystal structure derived for this polymer using model compounds. Furthermore, these patterns are quite similar to that obtained for a variety of pyrolized aromatic organic molecules, suggesting substantial reaction that is of a statistical nature. Quantum chemical calculations are presented for structurally ideal PPN, which suggest a small (0.3 eV) or vanishing bandgap, depending upon the precise molecular geometry and the nature of interchain coupling.