Conjugated polymers as light emitting materials have attracted considerable attention during the past several decades. There is substantial ongoing research towards the design of blue light emitting materials for OLEDs based on conjugated polymers. The conjugation length

steric hindrance within the polymer

must be controlled for such purpose. It is well known that the binaphthyl unit possesses a large dihedral angle ranging from 60° to 120°. Therefore

the conjugation of the binaphthyl-containing polymers can be interrupted by the highly twisted binaphthyl unit. In addition

the highly twisted structure will reduce the intermolecular interaction of the polymers. As a result

the binaphthyl-containing polymers will have high quantum efficiency and good solubility. Binaphthalene chromophores were introduced into the backbone of conjugated copolymers with different aromatic groups by Wittig or Wittig-Horner reaction

three linear copolymers and a hyperbranched (copolymer) containing binaphthyl unites were synthesized. All the copolymers were characterized by FT-IR

(

1

H NMR.) They were readily dissolved in the common solvents such as tetrahydrofuran(THF)

dichloromethane

and chloroform. Their photophysical properties have been studied. The results indicated that all copolymers show pure blue light emitting. It is mentionable that the hyperbranched copolymer BN-TPPV shows the highest quantum efficiency (95%) among the four copolymers

which exhibits two emission band peaked at 393 nm and 410 nm in chloroform and one broad emission band peaked at 428 nm in solid film. Cyclic voltammetry was employed to investigated the electrochemical properties of the polymers

their band gaps were ranging from 2.76 eV to 3.05 eV

this result testified that the polymers

BN-PPV

BN-PBPV

BN-TPPV

have the potential to be applied as blue light emitting materials. The results show that it is a practical way to prepare blue light emitting polymers by incorporating binaphthyl into polymer chain.