Structural and electronic characterization of chemical and conformational defects in conjugated polymers

Quantum chemical analyses of poly(p-phenylenevinylene) (PPV)-based polymers with conformational and chemical defects are presented. It is shown that d efects leading to tetrahedral kinks in the polymerization direction that we re proposed previously to explain the optical anisotropy of polymer films ( Hu et al. Nature 2000, 405, 1030) are indeed energetically stable. These de fects are shown not to affect the primary electronic absorption band, but t hey may localize the electron-hole excitation in one segment of the polymer chain.