Synthesis of Dendritic Oligo-Spiro(fluorene-9,9′-xanthene) Derivatives with Carbazole and Fluorene Pendants and their Thermal, Optical, and Electroluminescent Properties

Two novel spiro-configured ter(arylene-ethynylene) derivatives, TSF-Cz and TSF-F, have been designed and synthesized using spiro(fluorene-9,9'-xanthene) (SFX) as building blocks, introducing a hole-transporting carbazole and a fluorene chromophore as the peripheral functional group into the backbone through an oxygen atom. The two well-defined oligomers possess good solubility, film-forming quality, and high T g 's at 140 and 126 °C, respectively. In addition, these oligomers exhibit blue photoluminescence (PL) emission both in solution and solid states. The double-layered devices fabricated using the two materials as the emitter show a sky-blue emission with a brightness and a current efficiency of 7 613 cd · m ―2 and 1.11 cd · A ―1 for TSF-Cz, and 1 507 cd · m ―2 and 0.36 cd · A ―1 for TSF-F, respectively.