Tetrapalladium-Containing Polyoxotungstate [PdII4(α‑P2W15O56)2]16–: A Comparative Study

The novel tetrapalladium­(II)-containing polyoxometalate [PdII4(α-P2W15O56)2]16– has been prepared in aqueous medium and characterized as its hydrated sodium salt Na16[Pd4(α-P2W15O56)2]·71H2O by single-crystal XRD, elemental analysis, IR, Raman, multinuclear NMR, and UV–vis spectroscopy. The complex exists in anti and syn conformations, which form in a 2:1 ratio, and possesses unique structural characteristics in comparison with known {M4(P2W15)2} species. 31P and 183W NMR spectroscopy are consistent with the long-term stability of the both isomers in aqueous solutions.