Regioselective synthesis of substituted tetrahydrochromeno[2,3-d]pyrimidin-2-ones and -pyrimidine-2-thiones

Makarova, E.S.; Kabanova, M.V.; Filimonov, S.I.; Chirkova, Z.V.; Ivanovsky, S.A.; Shetnev, A.A.; Suponitsky, K.Y.

Авторы: Makarova E.S., Kabanova M.V., Filimonov S.I., Chirkova Zh V., Ivanovsky S.A., Shetnev A.A., Suponitsky K.Yu
Журнал: Russian Chemical Bulletin
Том: 72
Номер: 6
Год издания: 2023
Издательство: Springer Nature
Местоположение издательства: Switzerland
Первая страница: 1454
Последняя страница: 1465
DOI: 10.1007/s11172-023-3920-0
Аннотация: Single crystal X-ray diffraction (XRD), thermogravimetric, and dielectric studies are performed for single and polycrystalline samples of [(1–x)PbO + xWO3], 0≤ x ≤0.20, synthesized by solid phase reactions and crystallization of melts. The formation of previously unknown solid solutions based on the tetragonal form of lead oxide (α-PbO) – Pb1–2xWxO1+x, x ≈ 0.05 is observed. Single crystals of solid solutions are analyzed by XRD at 100 K and 293 K. It is found that their crystal structure isotypical to α-PbO is characterized by the orthorhombic space group Cmma with unit cell parameters (293 K) a = 5.510 Å, b = 5.570 Å, c = 5.301 Å. The main structural characteristics of solid solutions are determined. A structural model of the formation of solid solutions is established, according to which partial W substitution for Pb in α-PbO is accompanied by the inclusion of additional oxygen atoms to the location of lone pairs of substituted Pb2+ and the formation of vacancies in this cation sublattice. Temperature dependences of the permittivity and losses of solid solution crystals studied in the temperature range T = 80-570 K and at frequencies f = 1-1000 kHz do not have features characteristic of phase transitions.
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№	Имя	Описание	Имя файла	Размер	Добавлен
1.	Полный текст		st_eng.pdf	350,3 КБ	19 марта 2024 [kirshik]
2.	Экспертное заключение		fil_23a.pdf	61,8 КБ	20 марта 2024 [kirshik]

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Интеллектуальная Система Тематического Исследования НАукометрических данных

Regioselective synthesis of substituted tetrahydrochromeno[2,3-d]pyrimidin-2-ones and -pyrimidine-2-thionesстатья

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