Role of hydrogen-bonds in the crystal packing of three novel strandberg-type polyoxoanion compounds

Abstract

Three new supramolecular compounds [Cu0.5(H3O)2](H2prz)1.5[Mo5P2O23]·H2O (1); [4,4′-bpy]2[4,4′-H2bpy][H4Mo5P2O23]·4H2O (2); [4,4′-Hbpy][4,4′-bpy][H3Mo5P2O23]·2H3O (3); (pyz = pyrazine, bpy = 4,4′-bpyridine) have been hydrothermally synthesized and characterized by IR, UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), powder XRD analyses, TG analyses, cyclic voltammogram analyses, elemental analyses and single crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis reveals that there are multipoint hydrogen-bonding interactions in compounds 1–3. The structural features of the three compounds are that distinct one-dimensional (1D) chains are firstly formed, then the chains extend to form novel two-dimensional (2D) networks, finally unprecedented three-dimensional (3D) supramolecular host-guest structures were generated by Strandberg-type polyoxometaltes (POMs) and transition metal coordination complexes (TMCs) or organic ligands, and small organic guest molecules are exactly entrapped in void spaces via H-bonding interactions. The formations of the three distinct 3D supramolecular hybrid materials demonstrate the important role of H-bonds (non-covalent bond) in the construction of high dimensional architectures. Compounds 2–3 also show outstanding photocatalysis properties.