Noble Metals in Polyoxometalate Chemistry: Palladium-Containing Derivatives of the Monolacunary Keggin and Wells-Dawson Tungstophosphates

We have prepared the three novel Pd-II-containing tungstophosphates [Pd-2(alpha-PW11O39H0.5)(2)](9-) and two structural isomers of [Pd-2(alpha-P2W17O61Hn)(2)]((16-2n)-) via simple synthetic procedures and characterized their potassium salts by single-crystal X-ray diffraction, elemental analysis, and IR and multinuclear (P-31 and W-183) NMR spectroscopy. This study sheds light on the long-standing question about the nature and structure of the actual products formed in the reaction of Pd-II ions with monolacunary Keggin-type [alpha-XW11O39](n-) and Wells-Dawson-type [alpha(2)-P2W17O61](10-) heteropolytungstates.