Relations entre les tungstophosphates apparentés à l'anion PW12O403-. Synthèse et propriétés d'un nouveau polyoxotungstophosphate lacunaire K10P2W20O70·24H2O

Abstract

The relationship between all the polyoxotungstophosphates related to PW12O403-and P2W21O716-anions was established. A new compound K10P2W20O70was synthesized and characterized by infrared and Raman spectroscopy. These properties, and especially the31P and183W nuclear magnetic resonance spectra, allowed us to propose the structure. It is a lacunary species that reacts with Co(II) to give two 1-1 complexes, probably coordination isomers. In the presence of Co(I1) the A-type ? B-type PW9isomerization occurs in several steps, which are specified. The tungstophosphate ß isomers are less stable than the corresponding tungstosilicates or germanates, and ß-PW12was only identified as a reduced species PW12O404-.