Synthesis, Characterization And Photophysics Of The New Polyfluorenes And Its Derivatives Containing Electro-deficient Building Block

Polyfluorenes have emerged as very promising materials for blue emission due to their unique combination of high thermal stability, and high photoluminescence (PL) quantum yields in both solution and solid state. However, a major problem in using these kinds of materials in OLEDs is the undesirable lower energy emission band, turning the pure blue emission to blue-green color, due to the form of the excimer, the result of the chain aggregation. Another problem for the polyfluorenes is its poor electron injection and transporting ability.Our motivation for the present work was to synthesis of 5, 6-bis(2-bromo-9,9-dihexyl-9H-fluoren-7-yl)pyrazine-2,3-dicarbonitrile-containing polyfluorenes where the pyrazine unit is attached such that the polyfluorene backbone is kinked, thereby improving the chance of retention of the blue emission. We also try to import the electron injection and transporting ability of the polyfluorenes by employing the pyrazine...