1.含噻吩、芴基混成之星狀有機共軛材料 2.茚芴之共軛寡聚物的合成與性質研究

Abstract

近年來在許多文獻報導中發現，以噻吩(thiophene)為主體之有機材料已被廣泛的應用在各領域。儘管如此，以噻吩分子所形成之寡聚合物(Oligomer) 還是存在著螢光量子效率偏低之缺陷。因此本論文在化合物中心及外圍，分別引入苯環 (phenyl) 及螢光效率佳之芴基 (fluorene) 合成出一系列高螢光量子效率之有機共軛發光材料，結構如圖所示。其擁有可逆之氧化及還原訊號與相當高之熱穩定性。本論文第二部分是以茚芴(indenofluorene)為主體之有機共軛寡聚物，由於其短波長及寬能隙之特性，設計作為有機發光二極體之主體材料(host materials)。以茚芴主體之共軛長度將其分成InF3-tt、InF3-tp及InF4兩部分，而茚芴主體外圍帶上之芳香環基團，使其於排列時能增加分子間之立體障礙，減少分子間聚集的作用，降低有序之排列而提升其光色純度及玻璃轉換之溫度。除了具有良好之熱性質外，此系列材料亦擁有可分別進行可逆的氧化、還原反應之雙極性(bipolar)特性。

Oligothiophene have been used in many applications as active materials during the past years. Application in organic light emitting diodes would be limited due to lower quantum yield. We design in this thesis a novel series of starburst molecules based on thiophene and 9,9-ditolylfluorene hybridized. However, the bulkiness and rigidity of the terminal 9,9-ditolylfluorene moieties plays an important role to improve the quantum yield and thermal stability. As we expected that the PSFn in this study exhibit highly quantum yield (> 99 %) and show distinct and high glass transition temperatures from ranging from 166 to 205 ℃.The second part of this thesis is the synthesis and properties of indenofluorene-based conjugate materials. The short emission wavelength and large band gap indicate a great potential as host materials in organic light-emitting diodes. The compounds InF3-tt、InF3-tp and InF4 are different from the conjugation lengths on the core. In order to increase the steric hindrance, we have introduced numbers of aryl groups in the periphery to prevent intermolecular interactions and improve the morphological and thermal stability of the resulting organic materials. Energy level of InF3-tt、InF3-tp and InF4 could be determined using the data from cyclic voltammetry and absorption spectra. By calculating with the HOMO-LUMO band gap measured from the electrochemical processes, the values are 3.88 eV (InF3-tt)、3.84 eV (InF3-tp) and 3.64 eV (InF4).