TY - JOUR
T1 - Deprotonation-Induced and Ion-Pairing-Modulated Diradical Properties of Partially Conjugated Pyrrole-Quinone Conjunction
AU - Sugiura, Shinya
AU - Kubo, Takashi
AU - Haketa, Yohei
AU - Hori, Yuta
AU - Shigeta, Yasuteru
AU - Sakai, Hayato
AU - Hasobe, Taku
AU - Maeda, Hiromitsu
N1 - Funding Information:
This work was supported by JSPS KAKENHI grant numbers JP18H01968 and JP22H02067 for Scientific Research (B), JP19K05444 for Scientific Research (C), JP20H05863 and JP20H05865 for Transformative Research Areas (A) “Condensed Conjugation”, Ritsumeikan Global Innovation Research Organization (R-GIRO) project (2017–22 and 2022–27), JST SPRING grant number JPMJSP2101, and the Sasakawa Scientific Research Grant from the Japan Science Society. Theoretical calculations were partially performed using the Research Center for Computational Science, Okazaki, Japan (21-IMS-C077 and 22-IMS-C077), and the Research Institute for Information Technology, Kyushu University, Japan. The synchrotron radiation experiments were performed at BL02B1 (2021A1597) and BL40XU (2022A1483) of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI). We thank Dr. Nobuhiro Yasuda, JASRI/SPring-8, Prof. Kunihisa Sugimoto, Kindai University, and Prof. Osamu Tsutsumi, Ritsumeikan University, for single-crystal X-ray analysis, and Prof. Hitoshi Tamiaki, Ritsumeikan University, for various measurements.
Funding Information:
This work was supported by JSPS KAKENHI grant numbers JP18H01968 and JP22H02067 for Scientific Research (B), JP19K05444 for Scientific Research (C), JP20H05863 and JP20H05865 for Transformative Research Areas (A) “Condensed Conjugation”, Ritsumeikan Global Innovation Research Organization (R-GIRO) project (2017-22 and 2022-27), JST SPRING grant number JPMJSP2101, and the Sasakawa Scientific Research Grant from the Japan Science Society. Theoretical calculations were partially performed using the Research Center for Computational Science, Okazaki, Japan (21-IMS-C077 and 22-IMS-C077), and the Research Institute for Information Technology, Kyushu University, Japan. The synchrotron radiation experiments were performed at BL02B1 (2021A1597) and BL40XU (2022A1483) of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI). We thank Dr. Nobuhiro Yasuda, JASRI/SPring-8, Prof. Kunihisa Sugimoto, Kindai University, and Prof. Osamu Tsutsumi, Ritsumeikan University, for single-crystal X-ray analysis, and Prof. Hitoshi Tamiaki, Ritsumeikan University, for various measurements.
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/4/12
Y1 - 2023/4/12
N2 - Quinoidal molecules based on dipyrrolyldiketone boron complexes (QPBs), in which pyrrole units were connected by a partially conjugated system as a singlet spin coupler, were synthesized. QPB, which was stabilized by the introduction of a benzo unit at the pyrrole β-positions, formed a closed-shell tautomer conformation that showed near-infrared absorption. The deprotonated species, monoanion QPB- and dianion QPB2-, showing over 1000 nm absorption, were formed by the addition of bases, providing ion pairs in combination with countercations. Diradical properties were observed in QPB2-, whose hyperfine coupling constants were modulated by ion-pairing with π-electronic and aliphatic cations, demonstrating cation-dependent diradical properties. VT NMR and ESR along with a theoretical study revealed that the singlet diradical was more stable than the triplet diradical.
AB - Quinoidal molecules based on dipyrrolyldiketone boron complexes (QPBs), in which pyrrole units were connected by a partially conjugated system as a singlet spin coupler, were synthesized. QPB, which was stabilized by the introduction of a benzo unit at the pyrrole β-positions, formed a closed-shell tautomer conformation that showed near-infrared absorption. The deprotonated species, monoanion QPB- and dianion QPB2-, showing over 1000 nm absorption, were formed by the addition of bases, providing ion pairs in combination with countercations. Diradical properties were observed in QPB2-, whose hyperfine coupling constants were modulated by ion-pairing with π-electronic and aliphatic cations, demonstrating cation-dependent diradical properties. VT NMR and ESR along with a theoretical study revealed that the singlet diradical was more stable than the triplet diradical.
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U2 - 10.1021/jacs.3c01025
DO - 10.1021/jacs.3c01025
M3 - Article
C2 - 36976916
AN - SCOPUS:85151349695
SN - 0002-7863
VL - 145
SP - 8122
EP - 8129
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 14
ER -