Research output: Contribution to journal › Article › peer-review
Platform for High-Spin Molecules : A Verdazyl-Nitronyl Nitroxide Triradical with Quartet Ground State. / Tretyakov, Evgeny V.; Petunin, Pavel V.; Zhivetyeva, Svetlana I. et al.
In: Journal of the American Chemical Society, Vol. 143, No. 21, 02.06.2021, p. 8164-8176.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Platform for High-Spin Molecules
T2 - A Verdazyl-Nitronyl Nitroxide Triradical with Quartet Ground State
AU - Tretyakov, Evgeny V.
AU - Petunin, Pavel V.
AU - Zhivetyeva, Svetlana I.
AU - Gorbunov, Dmitry E.
AU - Gritsan, Nina P.
AU - Fedin, Matvey V.
AU - Stass, Dmitri V.
AU - Samoilova, Rimma I.
AU - Bagryanskaya, Irina Yu
AU - Shundrina, Inna K.
AU - Bogomyakov, Artem S.
AU - Kazantsev, Maxim S.
AU - Postnikov, Pavel S.
AU - Trusova, Marina E.
AU - Ovcharenko, Victor I.
N1 - Publisher Copyright: © 2021 Authors. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/6/2
Y1 - 2021/6/2
N2 - Thermally resistant air-stable organic triradicals with a quartet ground state and a large energy gap between spin states are still unique compounds. In this work, we succeeded to design and prepare the first highly stable triradical, consisting of oxoverdazyl and nitronyl nitroxide radical fragments, with a quartet ground state. The triradical and its diradical precursor were synthesized via a palladium-catalyzed cross-coupling reaction of diiodoverdazyl with nitronyl nitroxide-2-ide gold(I) complex. Both paramagnetic compounds were fully characterized by single-crystal X-ray diffraction analysis, superconducting quantum interference device magnetometry, EPR spectroscopy in various matrices, and cyclic voltammetry. In the diradical, the verdazyl and nitronyl nitroxide centers demonstrated full reversibility of redox process, while for the triradical, the electrochemical reduction and oxidation proceed at practically the same redox potentials, but become quasi-reversible. A series of high-level CASSCF/NEVPT2 calculations was performed to predict inter- and intramolecular exchange interactions in crystals of di- and triradicals and to establish their magnetic motifs. Based on the predicted magnetic motifs, the temperature dependences of the magnetic susceptibility were analyzed, and the singlet-triplet (135 ± 10 cm-1) and doublet-quartet (17 ± 2 and 152 ± 19 cm-1) splitting was found to be moderate. Unique high stability of synthesized verdazyl-nitronylnitroxide triradical opens new perspectives for further functionalization and design of high-spin systems with four or more spins.
AB - Thermally resistant air-stable organic triradicals with a quartet ground state and a large energy gap between spin states are still unique compounds. In this work, we succeeded to design and prepare the first highly stable triradical, consisting of oxoverdazyl and nitronyl nitroxide radical fragments, with a quartet ground state. The triradical and its diradical precursor were synthesized via a palladium-catalyzed cross-coupling reaction of diiodoverdazyl with nitronyl nitroxide-2-ide gold(I) complex. Both paramagnetic compounds were fully characterized by single-crystal X-ray diffraction analysis, superconducting quantum interference device magnetometry, EPR spectroscopy in various matrices, and cyclic voltammetry. In the diradical, the verdazyl and nitronyl nitroxide centers demonstrated full reversibility of redox process, while for the triradical, the electrochemical reduction and oxidation proceed at practically the same redox potentials, but become quasi-reversible. A series of high-level CASSCF/NEVPT2 calculations was performed to predict inter- and intramolecular exchange interactions in crystals of di- and triradicals and to establish their magnetic motifs. Based on the predicted magnetic motifs, the temperature dependences of the magnetic susceptibility were analyzed, and the singlet-triplet (135 ± 10 cm-1) and doublet-quartet (17 ± 2 and 152 ± 19 cm-1) splitting was found to be moderate. Unique high stability of synthesized verdazyl-nitronylnitroxide triradical opens new perspectives for further functionalization and design of high-spin systems with four or more spins.
UR - http://www.scopus.com/inward/record.url?scp=85107710941&partnerID=8YFLogxK
U2 - 10.1021/jacs.1c02938
DO - 10.1021/jacs.1c02938
M3 - Article
C2 - 34019759
AN - SCOPUS:85107710941
VL - 143
SP - 8164
EP - 8176
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 21
ER -
ID: 28754077