The author of 《Regioregularity and Electron Deficiency Control of Unsymmetric Diketopyrrolopyrrole Copolymers for Organic Photovoltaics》 were Aoshima, Kenta; Nomura, Mayuka; Saeki, Akinori. And the article was published in ACS Omega in 2019. Formula: C7H3BrFN The author mentioned the following in the article:
Manipulating the electron deficiency and controlling the regioregularity of π-conjugated polymers are important for the fine-tuning of their electronic and electrochem. properties to make them suitable for an organic solar cell. Here, we report such a mol. design of unsym. diketopyrrolopyrrole (DPP) based copolymers with different aromatic side units of either thiophene (Th), pyridine (Py), or fluorobenzene (FBz). The unsym. electron acceptors of Th-DPP-Py and Th-DPP-FBz were polymerized with the electron donor of two-dimensional benzobisthiophene (BDT-Th), affording two regiorandom DPP copolymers. They exhibited contrasting MO levels and bulk heterojunction morphol. in methanofullerene-blended films, leading to power conversion efficiencies of 3.75 and 0.18%, resp. We further synthesized a regioregular DPP copolymer via sandwiching the centrosym. BDT-Th unit by two Th-DPP-Py units in an axisym. manner. The extensive characterization through morphol. observation, X-ray diffraction, and space-charge-limited current mobilities highlight the case-dependent pos./neg. effects of regioregularity and electron deficiency control. In the experiment, the researchers used many compounds, for example, 4-Bromo-2-fluorobenzonitrile(cas: 105942-08-3Formula: C7H3BrFN)
4-Bromo-2-fluorobenzonitrile(cas:105942-08-3) is used as a OLED intermediate, Pharmaceutical, electronic and chemical intermediate.Formula: C7H3BrFN It is used in the synthesis of heterocycles and liquid crystals.
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts