| Abstract
| - Four novel two-dimensional conjugated poly(p-phenylenevinylene) (PPV)-based molecules have beensynthesized, characterized, and evaluated for use in light-emitting diodes (LEDs). These novel molecules allcontain a tetra-substituted central phenyl ring, but the length, chemical structure, and placement of the armsis varied in order to tailor their hole and electron transport properties. The materials are all solution-processible,maintain conjugation through the arms and central core, and exhibit evidence of two- and possibly three-dimensional charge delocalization. The first molecule contains four phenylenevinylene arms with solubilizingoctyloxy-substituted units. Two of the molecules have two phenylenevinylene arms and two oxadiazole armsthat are placed ortho or para with respect to each other. The fourth molecule contains four cyano-phenylenevinylene arms with solubilizing octyloxy groups at the ends of each arm. As a class these moleculesall have large Stokes shifts in films, although the propensity for π−π stacking varies between the molecules.The oxadiazole-containing molecules show promise for applications in single-layer LEDs.
|
