Optical and electrical properties of π-conjugated polymers based on electron-rich 3,6-dimethoxy-9,9-dihexylfluorene unit

A new family of pi-conjugated polymers has been developed using 3,6-dimethoxy-9,9-dihexylfluorene as an electron-rich unit. These electroactive and photoactive polymers have been prepared from nickel(0)-mediated coupling or by palladium-catalyzed Suzuki coupling. These new 3,6-dimethoxy-9,9-dihexylfluorene-based copolymers have demonstrated emission spanning the entire visible spectrum. Moreover, all of these polymers show reversible electroactivity upon reduction and oxidation, and as expected, the presence of methoxy groups onto the fluorene moiety increases the ionization potential of the resulting copolymers by about 0.2 eV when compared with some 9,9-dihexylfluorene-based copolymers. The reduction of the energy barrier for the injection of holes in related polymeric light-emitting devices should contribute to the enhancement of their performances.