Voltammetric and Spectroscopic Studies of α- and β-[PW12O40]3– Polyoxometalates in Neutral and Acidic Media: Structural Characterization as Their [(n-Bu4N)3][PW12O40] Salts
| Autor: | Hiromi Ota, Motoo Shiro, SiXuan Guo, John F. Boas, Alan M. Bond, Keisuke Kodani, Tadaharu Ueda |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Inorganic Chemistry. 56:3990-4001 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/acs.inorgchem.6b03046 |
| Popis: | The structure of the Keggin-type β-[PW12O40]3– (PW12) polyoxometalate, with n-Bu4N+ as the countercation, has been determined for the first time by single-crystal X-ray analysis and compared to data obtained from a new determination of the structure of the α-PW12 isomer, having the same countercation. Analysis of cyclic voltammograms obtained in CH3CN (0.1 M [n-Bu4N][PF6]) reveals that the reversible potential for the β-PW12 isomer always remains ca. 100 mV more positive than that of the α-PW12 isomer on addition of the acid CF3SO3H. Simulations of the cyclic voltammetry as a function of acid concentration over the range 0–5 mM mimic experimental data exceptionally well. These simulation–experiment comparisons provide access to reversible potentials and acidity constants associated with α and β fully oxidized and one- and two-electron reduced systems and also explain how the two well-resolved one-electron W(VI)/W(V) processes converge into a single two-electron process if sufficient acid is present. 183W ... |
| Databáze: | OpenAIRE |
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