Abstract Different methods have been explored to synthesize the first soluble cyclopenta[2,1-b;3,4-b′]dithiophen-4-one (CPDTO) homopolymer, poly(3,5-didodecylCPDTO), C12-PCPDTO. Oxidation of the monomer C12-CPDTO by FeCl3 only gave oligomers. Elemental and NMR analyses indicated that oligomers were chlorinated at the both ends. A mechanism is proposed to explain why chlorination is so problematic for oxidation polymerization of C12-CPDTO in comparison to 3-alkylthiophene. Dedoping of the oligomers was also investigated. Pd-catalyzed reaction of dibromo monomer and hexamethylditin yielded C12-PCPDTO-Sn with an Mw of 22,816. This polymer exhibits a bimodal distribution of molecular weight, which is rationalized by an analysis of relative reactivities of species present in the polymerization process. The optical bandgap is 1.85 eV in both chloroform solution and film, much larger than that of electrochemically synthesized unalkylated PCPDTO film. This is explained by poor backbone planarity as predicted by DFT calculation of C2-CPDTO oligomers. The efficient synthesis of the monomer and the polymer paves the way for future synthesis of soluble planar CPDTO homopolymers with alternating alkylated and non-alkylated CPDTO units.

中文翻译：

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poly(3,5-didodecyl-cyclopenta[2,1-b;3,4-b']dithiophen-4-one)的合成与表征

摘要 已经探索了不同的方法来合成第一种可溶性环戊二烯[2,1-b;3,4-b']二噻吩-4-one (CPDTO) 均聚物、聚(3,5-二十二烷基CPDTO)、C12-PCPDTO。用 FeCl3 氧化单体 C12-CPDTO 只得到低聚物。元素和 NMR 分析表明低聚物的两端都被氯化。提出了一种机制来解释为什么与 3-烷基噻吩相比，氯化对于 C12-CPDTO 的氧化聚合如此成问题。还研究了低聚物的去掺杂。二溴单体和六甲基二锡的 Pd 催化反应产生 Mw 为 22,816 的 C12-PCPDTO-Sn。这种聚合物表现出双峰分子量分布，这可以通过分析聚合过程中存在的物质的相对反应性来合理化。光学带隙为 1。在氯仿溶液和薄膜中均为 85 eV，远大于电化学合成的未烷基化 PCPDTO 薄膜。这可以通过 C2-CPDTO 低聚物的 DFT 计算预测的较差的骨架平面度来解释。单体和聚合物的有效合成为未来合成具有交替烷基化和非烷基化 CPDTO 单元的可溶性平面 CPDTO 均聚物铺平了道路。