Synthesis and Characterization of Thiadiazolo[3,4-g]quinoxaline Based p-Conjugated Copolymers with Tunable Band Gaps
作者:Feng Tao、Zheng Wang、Zuojia Li、Kai Li、Ying Li、Qiang Peng
DOI:10.14233/ajchem.2013.14934
日期:——
A series of alternating conjugated copolymers based on thiadiazolo[3,4-g]quinoxaline units and different electron-donating units, such as fluorene, benzene and thiophene, with donor (D)-acceptor (A) alternating structures have been synthesized by palladium catalyzed Sonogashira condensation polymerization. The resulting copolymers P1, P2 and P3 were characterized by NMR, IR, gel permeation chromatography, thermogravimetric analysis and differential scanning calorimetry. Their optical and electronic properties can be facilely fine-modulated by adjusting the structures of different aromatic or heteroaromatic blocks. UV-visible absorption and cyclic voltammetry measurements indicate that all these copolymers have low band gaps due to the strong interaction between the donor and thiadiazolo[3,4-g]quinoxaline segments. Polymer P1 exhibits highest HOMO energy level, which can be expected to obtain high open-circuit voltage (Voc) from the fabricated PSCs. Polymer P3 based on thiophene and thiadiazolo[3,4-g]quinoxaline show smallest band gap and best absorption of sun light even in near-infrared (NIR) region. Preliminary studies imply that these copolymers can be used as efficient polymer donor materials in polymer solar cell applications.
一系列基于噻二唑[3,4-g]喹噁啉单元和不同给电子单元(如芴、苯和噻吟)的交替共轭共聚物,具有给体(D)-受体(A)交替结构,已通过钯催化的Sonogashira缩聚反应合成。所得共聚物P1、P2和P3通过核磁共振、红外光谱、凝胶渗透色谱、热重分析和差示扫描量热法进行表征。通过调节不同芳香或杂芳环的结构,可以方便地调节它们的光学和电子性质。紫外-可见吸收和循环伏安法测量表明,由于给体和噻二唑[3,4-g]喹噁啉片段之间的强相互作用,所有这些共聚物都具有较低的带隙。聚合物P1表现出最高的HOMO能级,这有望从制备的聚合物太阳能电池中获得高开路电压(Voc)。基于噻吟和噻二唑[3,4-g]喹噁啉的聚合物P3显示出最小的带隙,在近红外(NIR)区域也具有最佳的太阳光吸收。初步研究表明,这些共聚物可用作聚合物太阳能电池应用中的高效聚合物给体材料。