The first 3D framework based on Dawson-like [SbW18O60]9− polyoxoanions

Two new 3D framework solids based on tungstoantimonate [H2bpy]2[Ni(bpy)(Hbpy)2HSbW18O60]·4H2O (1) and [H2bpy]2[Cu(bpy)(Hbpy)2HSbW18O60]·5H2O (2) (bpy = 4,4′-bipyridine) have been synthesized hydrothermally and structurally characterized by elemental analyses, IR spectra, thermal stability analyses, and single-crystal X-ray diffraction analysis. Structure analysis reveals that both of the structures exhibit 3D host frameworks constructed from the non-classical Dawson-like [SbW18O60]9− polyoxoanions building units and 1D coordination cationic chains ([Ni(bpy)(Hbpy)2]n4n+ for 1 or [Cu(bpy)(Hbpy)2]n4n+ for 2), which represent the first 3D frameworks composed of Dawson-like [SbW18O60]9− polyoxoanions. Furthermore, the compound 2-modified carbon paste electrode (2-CPE) displays good electrocatalytic activity toward the reduction of nitrite.