Synthesis, Structure and Property of a Dawson-type Arsenomolybdate with an Appended As super(III) Cap

An inorganic-organic hybrid compound, (H sub(2)bpy) sub(3)[As super(III)As sub(2) super(V)Mo sub(15) super(VI)Mo sub(3) super(V)O sub(62)].3H sub(2)O (bpy: 4,4'-bipyridine) (1) has been synthesized under hydrothermal conditions and characterized by elemental analysis, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction, IR spectrum, UV-Vis spectrum, thermogravimetric analysis and single-crystal X-ray diffraction. The crystallographic analysis reveals that compound 1 is composed of a Wells-Dawson polyoxoanion [As sub(2) super(V)Mo sub(15) super(VI)Mo sub(3) super(V)O sub(62)] super(9-) with the mixed valence of Mo super(V,VI), which acts as a tetradentate ligand coordinating with the As super(III) cation to form the mixed valence As super(III,V) containing arsenomolybdate with the single cap structure in a chelate coordination mode. In the solid state, compound 1 shows a 3D supramolecular structure through hydrogen-bonding interactions (C-H...O, N-H...O, N-H...N). In addition, compound 1 exhibits reversible multi-electron redox processes and effective electrocatalytic activities towards the reduction of H sub(2)O sub(2), NaNO sub(2) and KBrO sub(3). Moreover, compound 1 is used as a reducing agent of the graphene oxide to prepare graphene by a green chemistry type one-step synthesis method, which is characterized by XPS, Raman spectroscopy, PXRD, IR, scanning electron microscopy and transmission electron microscopy.