Three new three-dimensional organic–inorganic hybrid compounds based on PMo12O40n− (n = 3 or 4) polyanions and CuI–pyrazine/CuI–pyrazine–Cl porous coordination polymers

Abstract

Three new organic–inorganic hybrid compounds based on PMo₁₂O₄₀ⁿ⁻ (n = 3 or 4) polyanions and Cu^I–pz/Cu^I–pz–Cl porous coordination polymers: [Cu^I(pz)]₃[PMo^VI₁₂O₄₀] (1), [Cu^I(pz)_1.5]₄[PMo^VMo^VI₁₁O₄₀]·pz·2H₂O (2), [Cu^I₃(pz)₃Cl][Cu^I₂(pz)₃(H₂O)][PMo^VMo^VI₁₁O₄₀] (3) (pz = pyrazine) have been hydrothermally prepared and characterized by elemental analysis, IR, TG, XRD, XPS and single-crystal X-ray diffraction. Compound 1 presents a three-dimensional Cu^I–pz framework with cube-like chambers, into which PMo^VI₁₂O₄₀³⁻ Keggin ions are incorporated. Compound 2 shows a three-dimensional sandwich-like framework, and PMo^VMo^VI₁₁O₄₀⁴⁻ polyanions are located in the octagonal voids of every two-dimensional Cu^I–pz 4¹8² network structure. Compound 3 exhibits a two-dimensional Cl-bridged Cu^I–pz–Cl double-layer structure, and two kinds of PMo^VMo^VI₁₁O₄₀⁴⁻ polyanions as bridging linkers connect two adjacent double-layers to form a three-dimensional organic–inorganic framework through Cu^I–O bonds. Additionally, their electrochemical characters, electrocatalytic behaviors and solid state fluorescent properties at room temperature have been investigated in detail.