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Rare-Earth Metal (Pr(III), Тb(III), Ho(III), and Er(III))Complexes with 2-Mercaptopyridine-N-oxide:Synthesis, Structures, and Propertiesстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 13 июля 2022 г.
- Авторы: Shtefanets V.P., Shilov G.V., Kunitsyna E.I., Morgunov R.B., Sanina N.A., Aldoshin S.M.
- Журнал: Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya
- Том: 48
- Номер: 7
- Год издания: 2022
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 436
- Последняя страница: 451
- Оригинальные версии: Синтез, строение и свойства комплексов редкоземельных металлов (Pr(III), Tb(III), Ho(III) и Er(III))C 2-меркаптопиридин-N-оксидом
- DOI: 10.1134/S1070328422070089
- Аннотация: Four compounds are synthesized by the reactions of rare-earth metal(III) nitrates with 2-mercaptopyridine-N-oxide (HSC5H4NO) in water-alkaline solutions: [Pr2(SC5H4NO)6(H2O)2] (I), [Tb2-(SC5H4NO)6(H2O)2] (II), [Ho2(SC5H4NO)6(H2O)2] (III), and [Er2(SC5H4NO)6(H2O)2] (IV). Their synthesisand results of X-ray diffraction studies are presented. Each metal ion in the binuclear complexes formsthe octacoordinated structure including two SC5H4NO ligands, which coordinate each metal ion (3+) via thechelate mode (through S and O), two bridging oxygen atoms belonging to two SC5H4NO, and two moleculesof coordination water. The product χT and effective magnetic moment (μeff) remain unchanged in the synthesizedcomplexes in the temperature range from 300 to 150 K as found by SQUID magnetometry. At T <150 K in complexes I (Т < 30 K) and II (T < 50 K), μeff decreases with decreasing temperature, which possiblyindicates a magnetic transition and an antiferromagnetic interaction between the Pr3+ and Tb3+ ions. Anincrease in μeff with decreasing temperature and a sharp decrease at T < 10 K are observed in complex III,whereas in complex IV μeff increases smoothly with decreasing temperature. This can indicate the appearanceof ferromagnetic correlations in complex IV. No magnetic relaxation response is observed for complex I in thewhole frequency range of the alternating field (AC) HAC from 0.2 to 1400 Hz both in the bias field and withoutit. The field dependences of the magnetic moment at 2 and 5 K для complexes II–IV are characteristic ofparamagnetics at these temperatures. At T = 2 K the samples exist in the same spin state as at T = 300 K: coolingdoes not change the spin state of the Tb3+, Ho3+, and Er3+ ions in the complexes. No magnetic hysteresisis observed at low temperatures (2 and 5 K) in these complexes. The dependences of the real and imaginarycomponents of the magnetic susceptibility on the AC frequency for complexes II–IV are obtained in theabsence of a direct field (DC) and in the bias field. The Cole-Cole diagrams demonstrate the relaxation modeof the domain wall motion and no shift of a maximum of the imaginary component with changing temperature(tunneling relaxation mechanism) in complexes II–IV.
- Добавил в систему: Алдошин Сергей Михайлович