Synthesis and characterization of star polyfluorenes with a C60 core

C60-cored star polyfluorenes were synthesized and fully characterized. A high yield (81%) hexakisaddition of C60 was developed by using Prato reaction and bulky fluorene addends. Suzuki polycondensation of the hexakisadducts of C60 carrying six 2-bromofluorene addends and AB-type monomer (2-bromo-9,9-dioctylfluorenyl-4,4,5,5-tetramethyl- [1,3,2]-dioxaborane) with Pd(PPh3)4 as the catalyst precursor afforded the desired C60-cored star polyfluorenes. Their three-dimensional structure can effectively reduce the aggregation of the polyfluorene chains. Annealing studies indicated that the C60-cored star polyfluorenes are of good color stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4696–4706, 2007