Platform for High-Spin Molecules: A Verdazyl-Nitronyl Nitroxide Triradical with Quartet Ground State

Platform for High-Spin Molecules: A Verdazyl-Nitronyl Nitroxide Triradical with Quartet Ground State Full article

Journal

Journal of the American Chemical Society
ISSN: 0002-7863

Output data

Year: 2021, Volume: 143, Number: 21, Pages: 8164–8176 Pages count : DOI: 10.1021/jacs.1c02938

Authors

Tretyakov E.V. ¹ , Petunin P.V. ² , Zhivetyeva S.I. ³ , Gorbunov D.E. ⁴ , Gritsan N.P. ⁴ , Fedin M.V. ⁵ , Stass D.V. ^4,6 , Samoilova R.I. ⁴ , Bagryanskaya I.Y. ³ , Shundrina I.K. ³ , Bogomyakov A.S. ⁴ , Kazantsev M.S. ³ , Postnikov P.S. ² , Trusova M.E. ² , Ovcharenko V.I. ⁵

Affiliations

1	N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Ave. 47, Moscow, 119991, Russian Federation
2	Tomsk Polytechnic University, Lenin Ave. 30, Tomsk, 634050, Russian Federation
3	N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, Ac. Lavrentiev Ave. 9, Novosibirsk, 630090, Russian Federation
4	V.V. Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Institutskaya Str. 3, Novosibirsk, 630090, Russian Federation
5	International Tomography Center, Siberian Branch of Russian Academy of Sciences, Institutskaya Str. 3a, Novosibirsk, 630090, Russian Federation
6	Novosibirsk State University, Pirogova Str. 2, Novosibirsk, 630090, Russian Federation

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. ©

Tretyakov E.V. , Petunin P.V. , Zhivetyeva S.I. , Gorbunov D.E. , Gritsan N.P. , Fedin M.V. , Stass D.V. , Samoilova R.I. , Bagryanskaya I.Y. , Shundrina I.K. , Bogomyakov A.S. , Kazantsev M.S. , Postnikov P.S. , Trusova M.E. , Ovcharenko V.I.
Platform for High-Spin Molecules: A Verdazyl-Nitronyl Nitroxide Triradical with Quartet Ground State
Journal of the American Chemical Society. 2021. V.143. N21. P.8164–8176. DOI: 10.1021/jacs.1c02938 WOS Scopus РИНЦ OpenAlex

Published online:	May 21, 2021
Published print:	Jun 2, 2021

Web of science:	WOS:000659443000032
Scopus:	2-s2.0-85107710941
Elibrary:	46808092
OpenAlex:	W3162343036

DB	Citing
Scopus	52
Web of science	57
Elibrary	62
OpenAlex	64