Peroxo-Containing Heteropolyanions [{XW ₃ O ₇ (O ₂ ) ₂ } ₂ O] ^6– (X = HPO ₄ ^2– , HAsO ₄ ^2– , CH ₃ AsO ₃ ^2–

We report the synthesis of the peroxo-containing heteropolyanions [{XW3O7(O2)2}2O]6– (X = HPO42–, HAsO42–, CH3AsO32–) obtained in aqueous medium via a straightforward one-pot reaction in the presence of H2O2. Single-crystal X-ray diffraction analysis reveals that all polyanions adopt dimeric structures composed of two {XW3} subunits interconnected by three oxo bridges. In each {XW3} unit, two peroxo groups are coordinated to tungsten centers situated in adjacent edge-sharing pentagonal bipyramids, whereas the third tungsten center adopts a regular octahedral environment bearing exclusively terminal oxo ligands. The solution stability of the polyanions was systematically investigated over a range of pH values and time intervals by multinuclear NMR spectroscopy. The antibacterial screening of the peroxo-tungstoarsenate(V) and its organoarsonate(V) derivative was performed against representative Gram-negative and Gram-positive bacterial strains.