A diprotonated hexatungstoplatinate(IV), Na6[H2PtW6O24]•22H2O

The novel protonated hexasodium dihydrogen hexatungstoplatinate(IV) doicosahydrate, Na-6[H2PtW6O24].22H(2)O, was crystallized in the triclinic system in space group P (1) over bar. The [H2PtW6O24](6-) polyanion has C-i ((1) over bar) symmetry. The identification of the protonated O atom in the polyanion is difficult because it does not form interpolyanion hydrogen bonds, and a clear difference was not found in the W-O(H) bond lengths or the W-O(H)-W bond angles to indicate protonation of the O atom.