我們利用簡易的合成方法成功地合成出一系列具有不同共軛長度及側鏈之寡聚芴分子。我們於芴基C9位置引入甲苯基或是2,2’-聯苯基,可增加分子之熱穩定性,並維持芴基本身所具有之高量子產率。我們測量各寡聚芴之光物理、熱穩定、電化學和載子傳輸率,再根據各分子之物理特性,應用於藍光發光元件、紫外光發光元件、紅色磷光主體材料、液晶材料及載子量測所需之電荷產生材料,皆有非常好之元件表現。 另一方面,我們利用Negishi和Suzuki偶合反應,成功地將多電子之塞吩環引入共軛鏈中,並進一步合成出具有不同共軛系統之寡聚物。透過測量化合物之光物理、熱穩定和電化學性質,探討分子結構與性質間之關係。
We have successfully synthesized homologous series of oligofluorenes with variety of C9 substituents and backbone lengths by successive Suzuki coupling reactions. The correlation between molecular structure and physical properties including thermal stability, fluorescent quantum yields, and emission wavelength etc, has been investigated systematically for probing the structure-physical property relationship. The bulky and rigid 9,9-diaryl substituents are significantly beneficial for their high morphological and thermal stability. The emission maxima of these oligomers were lying on the blue region and closely dependent on the conjugation length. Cyclic voltammetry experiments reveal that these oligofluorenes exhibit potential ambipolar carrier transport property. These intriguing characteristics render them as the most promising candidates for OLEDs. The UV-OLED and red electrophosphorecent devices have been achieved using these oligomers as emitter or host materials. On the other hand, We have also successfully synthesized a series of thiophene-embedded conjugated oligomer with variety of backbone lengths by successive Negishi and Suzuki coupling reactions. The physical properties of these novel oligofluorene analogues are significantly altered upon introducing thiophene units as constituents. The presence of the thiophene and their coplanarity with adjacent phenylene rings provides these molecules with promising properties. We are presently fabricating light-emitting devices that incorporate these molecules as active materials.