Version 1
: Received: 31 July 2023 / Approved: 1 August 2023 / Online: 1 August 2023 (09:44:53 CEST)
Version 2
: Received: 1 August 2023 / Approved: 2 August 2023 / Online: 2 August 2023 (05:04:34 CEST)
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. Catalysts2023, 13, 1206.
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, 13, 1206.
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. Catalysts2023, 13, 1206.
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, 13, 1206.
Abstract
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. 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 T on T with 12-membered looped uniform stacks gave the following best-fit parameters: for 1a, g = 2.01 ± 0.05, J/kB = –292 ± 10 K; for 1b, g = 2.04 ± 0.1J/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 fluorine atoms introduced into Blatter radicals on their structure and magnetic properties.
Chemistry and Materials Science, Electronic, Optical and Magnetic Materials
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received:
2 August 2023
Commenter:
Evgeny Tretyakov
Commenter's Conflict of Interests:
Author
Comment:
Dear Editors, we confirmed the title, added Ref 62 (it was missed), and remove a hyperlink in Ref 66. Also we corrected two misprints g = 2.04 ± 0.01 (on pages 1 and 9).
Commenter: Evgeny Tretyakov
Commenter's Conflict of Interests: Author