Two wide band gap alternating copolymers (PFOTPP1 and PFOTPP2) derived from 9

9-dioctylfluorene and 2

6-bis(3-bromophenyl)-4-phenylpyridine (TPP1)

2

6-diphenyl-4-(3

5-dibromophenyl)pyridine (TPP2) were synthesized by Suzuki coupling reaction.The resulted polymers are soluble in common organic solvents such as toluene chloroform etc.The maximal absorption peaks of PFOTPP1 are around 325 nm in THF solution and 329 nm in solid thin film

The maximal absorption peaks of PFOTPP2 are around 329 nm in THF solution and 331 nm in solid thin film.PFOTPP1 and PFOTPP2 show two photoluminescence peaks around 367 nm and 383 nm in THF solution

and around 395 nm and 413 nm in solid thin film

respectively.The LUMO levels of PFOTPP1 and PFOTPP2 are around -253 eV and -264 eV.The glass-transition temperature of PFOTPP1 and PFOTPP2 is around 145℃ and 152℃

respectively.The thermal degradation temperature of PFOTPP1 and PFOTPP2 is above 400℃.It indicates that the energy levels of the polymers are widened and the LUMO levels of the polymers are increased with introducing the triphenylpyridine unit into the polyfluorene back bone.