Molybdophosphate heteropoly blues: Electron-transfer reactions in aqueous solutions as studied by NMR

Reduction of heteropolyacid H3[PMo12O40]·aq has been followed quantitatively by 31P NMR in its dilute aqueous solutions. The HPA anions (“blues”) reduced by one, two and four electrons were detected, and their relative concentrations were evaluated at different total degrees of reduction. The rate constants of the intermolecular electron transfer have been estimated for differently reduced species from their NMR line widths and intensities and compared with the calculated rate constants for the outer-sphere electron-transfer mechanism.

Graphical abstractReduction of heteropolyacid H3[PMo12O40] has been studied by 31P NMR in its dilute aqueous solutions. The rate constants of the intermolecular electron transfer between differently reduced species have been estimated from their NMR line widths and intensities.Figure optionsDownload full-size imageDownload as PowerPoint slide