Three new multidimensional organic-inorganic hybrids based on polyoxometalates and copper coordination polymers with 4,4′-bipyridine ligands

Three new organic-inorganic hybrid materials with 4,4′-bipy ligands and copper cations as linkers, Cu^II(H₂O)(4,4′-bipy)₂]Cu^II(H₂O)(4,4′-bpy)₂]₂HCu^IIP₈Mo₁₂O₆₂H₁₂] · 5H₂O (1), Cu^I(4,4′-bipy)]Cu^II(4,4′-bipy)]₂ (BW₁₂O₄₀) · (4,4′-bipy) · 2H₂O (2) and Cu^I (4,4′-bipy)]₃ (PMo₁₂O₄₀) · (pip) · 2H₂O (3) (pip = piperazine; 4,4′-bipy = 4,4′-bipyridine), have been hydrothermally synthesized. The single X-ray structural analysis reveals that the structure of 1 is constructed from Cu(H₂O)(4,4′-bipy)₂] complexes into a novel, three-dimensional supermolecular network with 1-D channels in which CuP₄Mo₆]₂ dimer clusters reside. To the best of our knowledge, compound 1 is the first complex in which the P₄Mo₆] clusters have been used as a non-coordinating anionic template for the construction of a novel, three-dimensional supermolecular network. Compound 2 is constructed from the six-supported BW₁₂O₄₀]⁵⁻ polyoxoanions and Cu^I(4,4′-bipy)] and Cu^II(4,4′-bipy)] groups into a novel, 3-D network. Compound 3 exhibits unusual 3-D supramolecular frameworks, which are constructed from tetrasupporting PMo₁₂O₄₀]³⁻ clusters and Cu^I (4,4′-bipy)_n] coordination polymer chains. The electrochemical properties of 2 and 3 have been investigated in detail.