@article{56e3f575dc0346c7b8e8bd068f005fc7,
title = "Curved Perylene Diimides Fused with Seven-Membered Rings",
abstract = "Curved perylene diimides fused with seven-membered rings have been synthesized using a regioselective bay-functionalization method and Pd-catalyzed intramolecular C−H/C−Br coupling reaction. X-Ray analysis and temperature-dependent NMR spectroscopy revealed the curved molecular structure with a certain degree of conformational flexibility. The curved and expanded π-conjugation altered the electronic properties while retaining the intrinsic properties of the parent perylene diimide. Despite the absence of solubilizing N-substituents, the curved perylene diimides showed sufficient solubility for application in solution-processed organic photovoltaic devices. The devices showed superior performance with a power conversion efficiency of up to 2.76% due to suppressed charge recombination. Our detailed investigations suggest that the introduction of a curved structure enables the removal of the bulky N-substituents, which is an effective way to achieve a thin-film morphology suitable for photoelectric conversion.",
keywords = "conformational flexibility, curved π-system, organic photovoltaics, perylene diimide, seven-membered ring",
author = "Keisuke Fujimoto and Seiichiro Izawa and Ayumu Takahashi and Toshiyasu Inuzuka and Kazutaka Sanada and Masami Sakamoto and Yasuo Nakayama and Masahiro Hiramoto and Masaki Takahashi",
note = "Funding Information: The authors thank Prof. Dr. Kazutaka Hirakawa at Shizuoka University for fluorescence lifetime measurements. YN thanks Dr. Tomoyuki Koganezawa of JASRI for his experimental support. This work was partly supported by Nanotechnology Platform Program (Molecule and Material Synthesis), JSPS KAKENHI (Grant‐in‐Aid for Young Scientists, No. 18K14115 and 19K15536) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, and grants from Toukai Foundation for Technology, Mazda foundation, and the Kao Foundation for Arts and Sciences. A part of this work was performed under approval of Japan Synchrotron Radiation Research Institute (JASRI) [2020A1627]. Funding Information: The authors thank Prof. Dr. Kazutaka Hirakawa at Shizuoka University for fluorescence lifetime measurements. YN thanks Dr. Tomoyuki Koganezawa of JASRI for his experimental support. This work was partly supported by Nanotechnology Platform Program (Molecule and Material Synthesis), JSPS KAKENHI (Grant-in-Aid for Young Scientists, No. 18K14115 and 19K15536) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, and grants from Toukai Foundation for Technology, Mazda foundation, and the Kao Foundation for Arts and Sciences. A part of this work was performed under approval of Japan Synchrotron Radiation Research Institute (JASRI) [2020A1627]. Publisher Copyright: {\textcopyright} 2021 Wiley-VCH GmbH Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",
year = "2021",
month = mar,
day = "15",
doi = "10.1002/asia.202100066",
language = "English",
volume = "16",
pages = "690--695",
journal = "Chemistry - An Asian Journal",
issn = "1861-4728",
publisher = "John Wiley and Sons Ltd",
number = "6",
}