Sh. Shin et al., Synthesis and luminescent properties of hyperbranched poly(P-phenylene)s by molecular architecture engineering, MOLEC CRYST, 349, 2000, pp. 423-426
synthesized by both Suzuki reaction and a nickel-catalyzed Grignard couplin
g reaction. P(4)8 and P(4)10 showed the UV absorption band at the longer wa
velength than P(3)8 and P(3)10, even though they have the same number of co
nsecutive phenyl groups. Photoluminescent (PL) spectra of P(4)8 and P(4)10
showed a blue emission at 490-496 nm, while P(3)8 and P(3)10 thin films sho
wed a maximum PL peak around 420-440 nm in the deep blue region.