Supramolecular stabilization of the phosphite-based polyoxomolybdate [Mo6(PO3)(HPO3)3O18]9−

A novel phosphite-based hetero-polyoxomolybdate, [Mo6(PO3)(HPO3)3O18]9−, has been isolated and structurally characterized. The most striking feature of this polyanion is the presence of peripheral phosphite groups linked to the MoO6 octahedra. In the solid state, this clusture shows strong hydrogen bonding interactions that apparently play a key role in its stabilization and isolation from solution.