Synthesis and Redox Characterization of the Polyoxo Anion, γ*-[S2W18O62]4-: A Unique Fast Oxidation Pathway Determines the Characteristic Reversible Electrochemical Behavior of Polyoxometalate Anions in Acidic Media
| Autor: | and Alan M. Bond, Anthony G. Wedd, Peter J. S. Richardt, Robert W. Gable |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Inorganic Chemistry. 40:703-709 |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | The synthesis and characterization of (Bu4N)4[S2W18O62]·1.23MeCN·0.27H2O are reported. It crystallizes in the monoclinic space group C2/c with a = 22.389(6) A, b = 22.104(3) A, c = 25.505(5) A, β = 95.690(15)°, V = 12560(5) A3, and Z = 4. The anion exists as the γ* isomer, the second example of this isomer type to be characterized structurally. The equivalent molybdenum salt occurs as the α isomer. γ*-[S2W18O62]4- in MeCN solution displayed four electrochemically reversible one-electron redox processes at E1/2 values of −0.24, −0.62, −1.18, and −1.57 V versus the Fc+/Fc couple. Upon addition of acid in MeCN/H2O (95/5 v/v), the two most cathodic processes converted to an overall two-electron process at −0.71 V. The total data suggested that this process actually comprises two one-electron transfer processes, occurring at different potentials, with associated proton-transfer reactions. The interpretation is supported by simulation of the effect of acid titration upon the cyclic voltammetry. While multiple p... |
| Databáze: | OpenAIRE |
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