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ESI-MS study of ionization pathways and cation-receptor properties of the iron(II) mono- and bis-clathrochelatesстатья
Статья опубликована в журнале из списка RSCI Web of Science
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из перечня ВАК
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 24 марта 2017 г.
- Авторы: Varzatskii O.A., Shul'ga S.V., Lebed E.G., Kozlowski H., Gumienna-Kontecka E., Szyrwiel Ł., Voloshin Y.Z.
- Журнал: Макрогетероциклы
- Том: 7
- Номер: 3
- Год издания: 2014
- Издательство: Федеральное государственное бюджетное образовательное учреждение высшего образования "Ивановский государственный химико-технологический университет"
- Местоположение издательства: Иваново
- Первая страница: 302
- Последняя страница: 310
- DOI: 10.6060/mhc140496v
- Аннотация: oximehydrazonate, dimethyl- and diamine-containing macrobicyclic analogs, and the cation-receptor properties of such cage compounds towards alkali metal cations (as individual ions or their mixtures) as well as the competitive complexation in the presence of 18-crown-6 were studied by ESI-MS method. Ionization of iron(II) mono- and bis-clathrochelates under the conditions of ESI-MS experiments was found to proceed via different pathways. The macrobicyclic iron(II) oximehydrazonate as an ionic associate of the clathrochelate cation with BF4 – anion undergoes the ionization by its heterolytic dissociation. The main pathways of ionization of the dioximate cage and bis-cage intracomplexes are substantially affected by ribbed substituents in their chelate fragments. The methyland amine-containing macrobicyclic complexes easily form anion-radical species by one-electron oxidation of their polyazomethine cage frameworks, whereas in the case of iron(II) dihalogenoclathrochelates the most intensive peaks correspond to their ionic associates with monocharged alkali metal cations. ESI-MS positive-mode spectrum of the iron(II) hexachloroclathrochelate contains no detectable peaks of the cationic species, which resulted either from its oxidation to the corresponding cation-radical or from its ionic associates with alkali metal cations. In the negative mode, an intensive peak assigned to the anion-radical product of one-electron reduction was observed. As ESI mass spectrometry allows maintaining precise concentrations of the complex under study and that of “cationization agents” (i.e., the compounds that promote formation of cationic species of the analyte and have been used in the case of low-ionizable complexes), the alkali metal tetraphenylborates were applied as such agents to study cation-receptor properties of the iron(II) mono- and bis-clathrochelates with ribbed substituents of the different nature towards these metal ions. Iron(II) monoclathrochelates form two types of ionic associates with such cations with both the 1:1 and 2:1 stoichiometries, which are more and less intensive in their ESI-MSs, respectively, whereas ESI-MSs of bis-cage complexes contain the intensive peaks of only 1:1 ionic associates with high affinity towards Cs+ cation.
- Добавил в систему: Лебедь Екатерина Геннадьевна