Iridium-Functionalized Polyfluorenes: Advantages And Limitations Of The Suzuki And Yamamoto Approaches

Four synthetic pathways leading toward iridium-functionalized polyfluorenes are compared: the metallopolymers have been synthesized via Suzuki and Yamamoto polycondensation reactions, and precursor routes as well as direct routes have been tested for both coupling protocols. The direct Yamamoto synthesis - using an appropriately functionalized iridium-complex as comonomer - is shown to be the most efficient method. The three competing routes produce the desired polymers too, but the materials are either lower in molar mass or less regular in molecular constitution. Exploratory analysis of the optical properties shows that the polyfluorene moieties dominate absorption and photoluminescence behavior in dilute solution, while luminescence originates mainly from the iridium complexes when solid-state samples are investigated.[GRAPHICS]