Dititanium-Containing 19-Tungstodiarsenate(III) [Ti2(OH)2As2W19O67(H2O)]8-(1):Synthesis, Structure, Electrochemistry, and Oxidation Catalysis Научная публикация
Журнал |
Chemistry - A European Journal
ISSN: 0947-6539 , E-ISSN: 1521-3765 |
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Вых. Данные | Год: 2007, Том: 13, Номер: 17, Страницы: 4733-4742 Страниц : 10 DOI: 10.1002/chem.200700043 | ||||||||
Ключевые слова | Electrochemistry homogeneous catalysis, Polyoxometalates, Self-assembly, Titanium, Tungsten | ||||||||
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Организации |
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Реферат:
The dititanium-containing 19-tungstodiarsenate(III) [Ti2(OH)2As2W19O67(H2O)]8− (1) has been synthesized and characterized by IR, TGA, elemental analysis, electrochemistry, and catalytic studies. Single-crystal X-ray analysis was carried out on Cs8[Ti2(OH)2As2W19O67(H2O)]⋅2 CsCl⋅12 H2O (Cs-1), which crystallizes in the monoclinic system, space group P21/m, with a=12.7764(19), b=19.425(3), c=18.149(3) Å, β=110.234(3)°, and Z=2. Polyanion 1 comprises two (B-α-AsIIIW9O33) Keggin moieties linked through an octahedral {WO5(H2O)} fragment and two unprecedented square-pyramidal {TiO4(OH)} groups, leading to a sandwich-type structure with nominal C2v symmetry. Synthesis of 1 was accomplished by reaction of TiOSO4 and K14[As2W19O67(H2O)] in a 2:1 molar ratio in aqueous, acidic medium (pH 2). Polyanion 1 could also be isolated as a tetra-n-butyl ammonium (TBA) salt, {(n-C4H9)4N}5H3[Ti2(OH)2As2W19O67(H2O)] (TBA-1). TBA-1 was studied by cyclic voltammetry in acetonitrile (MeCN) solutions containing 0.1 M LiClO4 and compared with the results obtained with Cs-1 in aqueous media. In MeCN, the TiIV and WVI waves could not be separated distinctly. An important adsorption phenomenon on the glassy carbon working electrode was encountered both in cyclic voltammetry and in controlled potential electrolysis and was confirmed by Electrochemical Quartz Crystal Microbalance (EQCM) studies on a carbon film. TBA-1, dissolved in MeCN, reacts with H2O2 to give peroxo complexes stable enough for characterization by UV-visible spectroscopy, cyclic voltammetry, and EQCM. TBA-1 shows high catalytic activity (TOF=11.3 h−1) in cyclohexene oxidation with aqueous H2O2 producing products typical of a heterolytic oxidation mechanism. The stability of TBA-1 under turnover conditions was confirmed by using IR, UV-visible spectroscopy as well as cyclic voltammetry.
Библиографическая ссылка:
Hussain F.
, Bassil B.S.
, Kortz U.
, Kholdeeva O.A.
, Timofeeva M.N.
, de Oliveira P.d.
, Keita B.
, Nadjo L.
Dititanium-Containing 19-Tungstodiarsenate(III) [Ti2(OH)2As2W19O67(H2O)]8-(1):Synthesis, Structure, Electrochemistry, and Oxidation Catalysis
Chemistry - A European Journal. 2007. V.13. N17. P.4733-4742. DOI: 10.1002/chem.200700043 WOS Scopus РИНЦ
Dititanium-Containing 19-Tungstodiarsenate(III) [Ti2(OH)2As2W19O67(H2O)]8-(1):Synthesis, Structure, Electrochemistry, and Oxidation Catalysis
Chemistry - A European Journal. 2007. V.13. N17. P.4733-4742. DOI: 10.1002/chem.200700043 WOS Scopus РИНЦ
Даты:
Поступила в редакцию: | 10 янв. 2007 г. |
Опубликована online: | 15 мая 2007 г. |
Опубликована в печати: | 4 июн. 2007 г. |
Идентификаторы БД:
Web of science | WOS:000247219900004 |
Scopus | 2-s2.0-34250321357 |
РИНЦ | 13554659 |
Chemical Abstracts | 2007:660115 |
Chemical Abstracts (print) | 147:267729 |
OpenAlex | W2065576367 |