N-Fluoroalkylpyrazolyl-substituted Nitronyl Nitroxides Научная публикация
Журнал |
Journal of Molecular Structure
ISSN: 0022-2860 , E-ISSN: 1872-8014 |
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Вых. Данные | Год: 2022, Том: 1269, Номер статьи : 133739, Страниц : DOI: 10.1016/j.molstruc.2022.133739 | ||||||||
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Реферат:
The aim of the study was to prepare and investigate structure and properties of a new series of stable nitronyl nitroxides bearing N-fluoroalkylpyrazolyl substituents. According to cyclic voltammetry data, a paramagnet with a difluoromethyl substituent can reversibly undergo electrochemical oxidation and reduction. In contrast, radicals with fluorinated ethyl substituents are electrochemically oxidized reversibly, but their electrochemical reduction is quasi-reversible. Molecular and crystal structures of the nitroxides were confirmed by single-crystal X-ray diffraction analysis. The crystal structures of the radicals were studied quantitatively in terms of pairwise interaction energies and energy framework analysis. Analysis of the energies of molecular pairs revealed that in crystalline phases of all nitroxides, the binding is the strongest in dimers assembled via C–H…O interactions of nitroxide O atoms with pyrazole and/or alkyl H atoms. Other dimers are formed predominantly by C–H…π interactions, and in some cases, their binding energy is almost equal to that for the aforementioned ones. The above contacts are complemented short contacts C–H…A and others, which predetermine the final crystal packing of radicals. A consequence of their packing is the geometry of relative arrangement of nitroxide groups and, above all, distances O…O between the oxygen atoms of the paramagnetic centers. These distances were found to exceed the sum of van der Waals radii; consequently, in solid phases of the paramagnets, weak antiferromagnetic exchange interactions are predominant (|J/kB| ≤ 2.74 K, H = –2J·S1S2.
Библиографическая ссылка:
Serykh A.
, Tretyakov E.
, Fedyushin P.
, Ugrak B.
, Dutova T.
, Lalov A.
, Korlyukov A.
, Akyeva A.
, Syroeshkin M.
, Bogomyakov A.
, Romanenko G.
, Artiukhova N.
, Egorov M.
, Ovcharenko V.
N-Fluoroalkylpyrazolyl-substituted Nitronyl Nitroxides
Journal of Molecular Structure. 2022. V.1269. 133739 . DOI: 10.1016/j.molstruc.2022.133739 WOS Scopus OpenAlex
N-Fluoroalkylpyrazolyl-substituted Nitronyl Nitroxides
Journal of Molecular Structure. 2022. V.1269. 133739 . DOI: 10.1016/j.molstruc.2022.133739 WOS Scopus OpenAlex
Идентификаторы БД:
Web of science: | WOS:000878184600010 |
Scopus: | 2-s2.0-85135127088 |
OpenAlex: | W4285678522 |