Keggin-Type Polyoxometalate Cluster Functionalized with Dinuclear M-H2biim (M = Cu, Ag) Metal–Organic Segments

Abstract

Three inorganic–organic hybrid complexes, [Cu2(H2biim)2(OH)2]2(SiW12O40)·2H2O (1), [Cu2(H2biim)2]2(SiW12O40)·2H2O (2) and [Ag2(H2biim)2]2(SiW12O40)·2H2O (3) (H2biim = 2, 2′-biimidazole), have been synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, PXRD, TG and single-crystal X-ray diffraction. The crystallographic analysis reveals that in compounds 1–3, the Keggin polyanions [α-SiW12O40]4− act as inorganic building blocks, which are linked with the dinuclear metal–organic units via Cu–O bonds in compound 1, or through supramolecular interactions in compounds 2 and 3. Compound 1 shows a 3D supramolecular structure constructed by net-like layers. Compounds 2 and 3 display 2D layer structures which were composed of wave-like chains. In addition, these compounds show electrochemical activities, and photoluminescence properties are measured in the solid state.