Effects of Difluorophenyl Substituents on Structural, Redox, and Magnetic Properties of Blatter Radicals

Effects of Difluorophenyl Substituents on Structural, Redox, and Magnetic Properties of Blatter Radicals Full article

Journal

Catalysts
ISSN: 2073-4344

Output data

Year: 2023, Volume: 13, Number: 8, Article number : 1206, Pages count : DOI: 10.3390/catal13081206

Authors

Gulyaev Dmitry ¹ , Serykh Andrey ^2,1 , Tretyakov Evgeny ¹ , Akyeva Anna ¹ , Syroeshkin Mikhail ¹ , Gorbunov Dmitry E. ³ , Maltseva Svetlana V. ^4,3 , Gritsan Nina P. ³ , Romanenko Galina ⁵ , Bogomyakov Artem ⁵

Affiliations

1	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Ave. 47, Moscow 119991, Russia
2	D. Mendeleev University of Chemical Technology of Russia, Miusskaya Pl. 9, Moscow 125047, Russia
3	V. V. Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Institutskaya Str. 3, Novosibirsk 630090, Russia
4	Department of Physics, Novosibirsk State University, Pirogova Street, 1, Novosibirsk 630090, Russia
5	International Tomography Center, Siberian Branch of Russian Academy of Sciences, Institutskaya Str. 3a, Novosibirsk 630090, Russia

Blatter radicals 1-(3,4-difluorophenyl)-(1a) and 1-(2,4-difluorophenyl)-3-phenyl-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl (1b) were prepared in good yields through oxidation of the corresponding amidrazones using MnO2 in dry CH2Cl2. Cyclic voltammetry showed that both radicals are oxidized and reduced chemically and electrochemically reversibly in accordance with −1/0 and 0/+1 processes. EPR spectroscopy indicated that spin density is mainly delocalized on the triazinyl moiety of the heterocycle. The structure of all paramagnets was unambiguously confirmed by single-crystal X-ray diffraction, and two different 1D chains of alternating radicals were identified. 3,4-difluorophenyl-derivatives 1a are packed into columns composed of two kinds of alternating centrosymmetric dimers, having comparatively short intermolecular distances. In crystals of 2,4-difluorophenyl-derivative 1b, the parallel arrangement of bicyclic moieties and phenyl rings favors the formation of 1D regular chains wherein the radicals are related by translation parallel to the crystallographic stacking axis. Magnetic susceptibility measurements in the 2–300 K region showed that in crystals of the radicals, strong antiferromagnetic interactions are dominant. Subsequent fitting of the dependence of χT on T with 12-membered looped stacks gave the following best-fit parameters: for 1a, g = 2.01 ± 0.05, J1/kB = −292 ± 10 K (according to BS-DFT calculations J2 = 0.12 × J1 and J3 = 0.61 × J1); for 1b, g = 2.04 ± 0.01 J1/kB = −222 ± 17 K. For comparison, in a nonfluorinated related radical, there are only very weak intermolecular interactions along the columns (J/kB = −2.2 ± 0.2 K). These results illustrate the magnitude of the influence of the difluorophenyl substituents introduced into Blatter radicals on their structure and magnetic properties.

Gulyaev D. , Serykh A. , Tretyakov E. , Akyeva A. , Syroeshkin M. , Gorbunov D.E. , Maltseva S.V. , Gritsan N.P. , Romanenko G. , Bogomyakov A.
Effects of Difluorophenyl Substituents on Structural, Redox, and Magnetic Properties of Blatter Radicals
Catalysts. 2023. V.13. N8. 1206 . DOI: 10.3390/catal13081206 WOS Scopus OpenAlex

Web of science:	WOS:001056876400001
Scopus:	2-s2.0-85169076747
OpenAlex:	W4385811806

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