Aryl trifluorovinyl ethers (TFVE) are versatile precursors to perfluorocyclobutyl aryl ether (PFCB) polymers. TFVE functionalized chromophores of a variety of colors have been synthesized for copolymerization to form PFCB polymers with tunable emissive properties. TFVE small molecule chromophores containing fluorene, benzothiadiazole, and bisthiophene show superb emissive properties and prove that the TFVE and PFCB structures have no effect on chromophore emission. Copolymerization of these chromophores with commercial TFVE monomers produced high molecular weight, thermally stable, emissive materials. With the use of trifunctional TFVE monomers these materials can be made into optical glasses. PFCB-phenylene vinylenes were prepared by Wittig polymerization and also confirm the lack of effect on emission by the PFCB linkage.
A synthetic method for the rapid, high yielding synthesis of tris-cyclometalated Ir[III] phosphors was developed. Microwave energy was used to reduce reaction times from 2 days to 30 min, and increase product yields from ~40% to ~90%. This synthesis was used to prepare dibromo functional Ir[III] phosphors for incorporation into conjugated organic polymer materials.
TFVE endcapped oligo(fluorene) derivatives were synthesized via a two part Suzuki coupling reaction. Use of different aryl dibromides afforded oligo(fluorene) derivatives containing benzothiadiazole, carbazole, and Ir[III] phosphors. These materials readily undergo thermal cyclopolymerization to form high molecular weight (~35,000 Mn), thermally stable, processable, highly emissive oligo(fluorene) block copolymers. These materials show promise as emissive materials for light emitting diodes.
Finally, copolymerization or blending of TFVE functionalized emissive materials was used to produce PFCB materials with unique emissive properties. White light photoluminescence is observed from TFVE endcapped oligo(fluorene) doped with trace amounts of TFVE endcapped oligo(fluorene-co-benzothiadiazole) and red Ir[III] phosphors. Purple photoluminescence is seen in blends of TFVE endcapped oligo(fluorene) and red Ir[III]. TFVE chromophores with emissions spanning the visible spectrum can be used to produce light of nearly any emissive color and with different charge mobility characteristics.