
TY  - JOUR
A1  - Smith, Bradley J. 
A1  - Patrick, Vincent A. 
T1  - Quantitative Determination of Aqueous Dodecatungstophosphoric Acid Speciation by NMR Spectroscopy
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2004
VL  - 57
IS  - 3
SP  - 261
EP  - 268
KW  - NMR &#8212; dodecatungstophosphoric acid &#8212; acid-base equilibrium &#8212; W &#8212; Keggin ions
UR  - https://doi.org/10.1071/CH02037 
N2  - The speciation and equilibria during base decomposition of &#945;-[PW12O40]3&#8211; have been determined using 31P and 183W NMR spectroscopy over the pH range 0.7&#8211;13.5. NMR spectroscopy was used to directly observe the polytungstate species in aqueous solution at high concentration (0.25 mol L&#8211;1) and follows the progressive decomposition of [PW12O40]3&#8211; to WO42&#8211; and PO43&#8211;. It was found unexpectedly in the pH range 1.2&#8211;2.3 that [PW12O40]3&#8211; did not decompose directly to [PW11O39]7&#8211; but first formed an equilibrium with [P2W18O62]6&#8211;, [P2W21O71]6&#8211;, and some new, stable, intermediate species before converting into &#945;-[PW11O39]7&#8211;. 
ER  -

