Star-like polyfluorenes based on 2,4,6,8, 10,12-hexabenzyl-2,4,6,8,10,12-hexaazaisowurtzitane caged-core: toward non-aggregating, blue-light-emitting polymers

Multi‐functionality compound 2,4,6,8,10,12‐hexa(p‐bromo)‐benzyl‐2,4,6,8,10,12‐hexaazaiso‐wurtzitane (Br‐HBIW) was synthesized and used for the core of star‐like polymers. Star‐like polyfluorene based on 2,4,6,8,10,12‐hexabenzyl‐2,4,6,8,10,12‐hexaazaisowurtzitane (HBIW) caged‐core was synthesized by Suzuki coupling method. The comparative studies between the star‐like polyfluorene and the linear polyfluorene based on UV–Vis and photoluminescence (PL) spectra revealed that the bulky HBIW cage could reduce the chain aggregation and π–π interaction, so brought about improved PL quantum efficiency and annealing PL stability. Such results could be owed to the successful suppression of excimers formation, which originated from the incorporation of the HBIW cage and star‐like architecture. Copyright © 2009 John Wiley & Sons, Ltd.