It is demonstrated that α,β-unsubstituted meso-positioning thienyl BODIPY is an electron deficient unit that leads to the development of ultra low optical band gap (E^opt_g < 1 eV) π-conjugated D–A quarterthiophene polymers. Furthermore, it is revealed that the optoelectronic, electrochemical and charge transporting properties of the resulting α,β-unsubstituted meso-positioning thienyl BODIPY quaterthiophene-based polymers are alkyl side chain positioning dependent. Tail-to-tail (TT) positioning of the alkyl side chains at the two central thiophenes of the quaterthiophene segment results in lower E^opt_g, higher energy levels and increased hole mobility as compared to head-to-head (HH) positioning. Finally, even though the synthesized polymers exhibit high electron affinity, higher even than that of the fullerene derivative [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM), they present only p-type behaviour in field effect transistors (FETs) independent of the alkyl side chain positioning.

中文翻译：

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α，β-未取代的内位噻吩基BODIPY：一种有前途的电子缺陷构建基，可用于开发近红外（NIR）p型供体-受体（DA）共轭聚合物†

结果表明，α，β-未取代的内位噻吩基BODIPY是一种电子不足的单元，可导致超低光学带隙（E ^opt _g <1 eV）π共轭D–A四噻吩聚合物的发展。此外，揭示了所得的α，β-未取代的介孔的噻吩基BODIPY四噻吩基聚合物的光电，电化学和电荷传输性质是烷基侧链定位依赖性的。烷基侧链在四噻吩链段的两个中心噻吩上的尾部尾部定位（TT），导致E ^opt _g降低与头对头（HH）定位相比，具有更高的能量水平和更高的空穴迁移率。最后，即使合成的聚合物表现出较高的电子亲和力，甚至高于富勒烯衍生物[6,6]-苯基-C _71-丁酸甲酯（PC ₇₁ BM），但它们在现场仅表现出p型行为。效应晶体管（FET）与烷基侧链的位置无关。