Synthesis and properties of polyfluorenes with phenyl substituents

Two new, alkoxyphenyl-substituted polyfluorenes, poly(9,9-bis(4'-hexyloxyphenyl)fluorene) and poly(9,9-bis(4'-hexyloxyphenyl)fluorene-alt-9,9-bis(4'-(2''-(2'''-methoxyethoxy)ethoxy)phenyl)fluorene), were synthesized using the Suzuki coupling reaction. The polymers were designed to obtain stable and efficient materials for light-emitting applications. Both polymers exhibit high PL-efficiencies and show PL- and EL-emission in the blue spectral region, with emission maxima in a narrow range around 427 nm. Annealing (200 DegC, 2 h) of polymer films exposed to normal indoor light in ambient atm., results in an addnl. emission band at higher wavelengths, indicating degrdn. by photo oxidn. [on SciFinder (R)