BOND ALTERNATION AND ELECTRONIC-STRUCTURE OF POLY(PERINAPHTHALENE)

It is shown on the Hartree-Fock level of theory that Peierls distortio ns of two different bond alternation patterns are possible for poly (p erinaphthalene). In the structurally related oligomeric systems, the s tabilization of a given type of bond length distortion results from th e boundary conditions as imposed by different end groups. For the poly mer, the re-re electron interaction is found to give preference to the bond alternation observed in oligorylenes. Nevertheless, the adiabati c potential energy surface has a double-well shape, with two almost de generate minima separated by a low potential barrier.