Coordination Chemistry of Polyoxomolybdates: The Structure of a Dodecanuclear Molybdate Cage Incorporating Hydrogen Squarate Ligands, [(C4H9)4N]4 [Mo12O36(C4O4H)4] · 10Et2O

Unusual in the polyoxometalate 1 are the hydrogen squarate ions and the presence not only of edge-sharing but also corner-sharing octahedra. An identification of the protonated sites was not possible, but an elemental analysis and the IR spectrum unequivocally confirm the presence of protons. Crystals of the Bu4N-salt of 1, which crystallizes with ten Et2O molecules per formula unit, readily lose two of the Et2O molecules; therefore the X-ray structure analysis had to be carried out in the presence of mother liquor.