S. Himeno et al., Cation effectsX on the voltammetric behavior of alpha-Keggin-type [SiMo12O40](4-) and [PMo12O40](3-) complexes in CH3COCH3 and CH3CN, J ELEC CHEM, 485(1), 2000, pp. 49-54
The effect of small cations such as H+, Li+ and Na+ on the voltammetric beh
avior of alpha-Keggin-type [SiMo12O40](4-) and [PMo12O40](3-) complexes was
investigated in CH3COCH3 and CH3CN. For the [SiMo12O40](4-) complex, the p
resence of Li+ or Na+ caused the one-electron waves to be converted into a
two-electron wave at ca. 0.3 V more positive than the first one-electron wa
ve. In the presence of Li+ or Na+, the [PMo12O40](3-) complex underwent a t
wo-electron reduction at the same potential as the original first one-elect
ron wave in CH3COCH3, whereas it exhibited only successive one-electron wav
es in CH3CN. The addition of a trace amount of H+ produced new two-electron
waves at more positive potentials. These findings give a clue to the under
standing of the reactivity of polyoxometalates as redox catalysts. (C) 2000
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