Tetradecanuclear Iron(III)-Oxo Nanoclusters Stabilized by Trilacunary Heteropolyanions

The tetrameric, multi-FeIII-containing polyoxotungstates [Fe14O6(OH)13­(P2W15O56)4]31– (1) and [Na2Fe14(OH)12­(PO4)4(A-α-XW9O34)4]20– (X = SiIV (2), GeIV (3)) have been successfully synthesized under conventional reaction conditions in aqueous, slightly acidic (1), or basic (2 and 3) media. Polyanions 1-3 were characterized in the solid state by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and magnetic studies, and in solution by electrochemistry.