Organic-inorganic hybrids constructed by Anderson-type polyoxoanions and copper coordination complexes

Four organic-inorganic hybrid compounds based on Anderson-type polyoxoanions, namely, {Cu(2,2′-bpy)(H₂O)₃]₂Cr(OH)₆Mo₆O₁₈]}{Cu(2,2′-bpy)(H₂O)Cl]Cu(2,2′-bpy)(H₂O)(NO₃)]Cr(OH)₆Mo₆O₁₈]}·18H₂O (1), Cu(2,2′-bpy)(H₂O)₂Cl]{Cu(2,2′-bpy)(H₂O)₂]Cr(OH)₆Mo₆O₁₈]}·4H₂O (2), (H₃O){Cu(2,2′-bpy)(H₂O)₂]₂Cu(2,2′-bpy)(H₂O)]₂}Cr(OH)₆Mo₆O₁₈]₃·36H₂O (3), and (H₃O){Cu(2,2′-bpy)(H₂O)₂]₂Cu(2,2′-bpy)(H₂O)]₂}Al(OH)₆Mo₆O₁₈]₃·33H₂O (4), were isolated by conventional solution method, and crystal structures have been determined by single-crystal X-ray diffraction. Among them, compound 1 displays a discrete supramolecular structure, compound 2 shows a chainlike structure with chloro-copper complexes as counteranions, and compounds 3 and 4 are isomorphic and exhibit unique 3D open frameworks with lattice water molecules residing in the channels. The compounds 3 and 4 represent the first example of 3D organic-inorganic hybrid compounds in the TMs/2,2′-bpy/POMs system. Investigation of the reaction conditions reveals that the geometry and size of the anions together with its coordinating abilities to the metal centers have a decisive influence on both the composition and the dimensionality of the final compounds.