Synthesis of novel polyfluorene with defined group in the center using aryl dipalladium complex as an initiator

Dinuclear Pd(II) complex DiPd–DPE with a bridging ligand C6H4OC6H4-4,4′ was successfully synthesized by double oxidative addition reaction of Pd(PCy3)4 with 4,4′-dibromodiphenyl ether in good yield. X-ray crystal structure analysis reveals that the Pd atoms have the nearly square-planar coordination geometry with the similar bond lengths of two Pd–Br as well as four Pd–P, implying that two Pd(II) centers have similar reactivity. Using the dinuclear Pd(II) complex DiPd–DPE as an initiator, novel polyfluorene (PF) with a defined group (C6H4OC6H4-4,4′) in the middle of polymer main chain was prepared, demonstrated by MALDI-TOF analysis.