Global Edge Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
Chem Soc Rev. 2011 May;40(5):2306-16. doi: 10.1039/c0cs00205d. Epub 2011 Mar 7.
After the historical development from the insoluble polyacetylene film to soluble and processible aromatic polymers, donor-acceptor-type aromatic polymers have recently emerged as a new class of semiconducting polymers. The polymer energy levels and band gaps can be tuned by the appropriate selection of the donor and acceptor moieties, and some of these polymers showed good optoelectronic or photovoltaic performances. The conventional synthetic method for achieving donor-acceptor-type aromatic polymers is based on the metal-catalyzed polycondensation between donor-type monomers and acceptor-type co-monomers. In this tutorial review, a new methodology for introducing donor-acceptor chromophores into semiconducting polymers is described. The donor-acceptor structures are constructed in the main chains and side chains of semiconducting polymers using a polymer reaction based on high-yielding addition reactions between the electron-rich alkynes and strong acceptor molecules, such as tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). Considering the p-type doping features of TCNE and TCNQ, the experimental procedure is the same as the conventional doping technique for semiconducting polymers. However, the resulting donor-acceptor type polymers are chemically stable due to the absence of unstable unpaired electrons (polarons). The donor-acceptor alternating polymers were achieved in one step from the precursor poly(aryleneethynylene)s and poly(arylenebutadiynylene)s. When the side chain alkynes were post-functionalized, the polymer energy levels were controlled by the species and amount of the employed acceptor molecules. These atom-economic acceptor additions satisfy most of the requirements of the "click chemistry" concept. In contrast to the conventional click chemistry reactions, the reactions between electron-rich alkynes and acceptor molecules provide a wide variety of polymers with promising optoelectronic applications.
在从不溶性聚乙炔薄膜到可溶性和可加工的芳香族聚合物的历史发展之后，供体-受体型芳香族聚合物最近作为一类新的半导体聚合物出现。聚合物的能级和带隙可以通过适当选择供体和受体部分来调节，其中一些聚合物表现出良好的光电或光伏性能。实现供体-受体型芳香族聚合物的常规合成方法基于供体型单体和受体型共聚单体之间的金属催化缩聚。在本综述中，描述了一种将供体-受体发色团引入半导体聚合物中的新方法。使用基于富电子炔烃与强受体分子（如四氰乙烯（TCNE）和 7,7,8,8-四氰基对醌二甲烷（TCNQ））之间高产率加成反应的聚合物反应，在半导体聚合物的主链和侧链中构建供体-受体结构。考虑到 TCNE 和 TCNQ 的 p 型掺杂特性，实验过程与半导体聚合物的常规掺杂技术相同。然而，由于不存在不稳定的未配对电子（极化子），因此所得的供体-受体型聚合物具有化学稳定性。从前驱体聚（芳基乙炔）和聚（芳基丁二炔）一步即可获得供体-受体交替聚合物。当侧链炔烃进行后功能化时，聚合物能级可通过所采用的受体分子的种类和数量来控制。这些原子经济性的受体加成反应满足“点击化学”概念的大多数要求。与传统的点击化学反应不同，富电子炔烃和受体分子之间的反应提供了具有广阔应用前景的各种聚合物。
