Three inorganic-organic hybrid complexes based on isopolymolybdate and derivatives of 1H-4-nitroimidazole

Three inorganic-organic diverse Cu^I motifs of [Cu^I(bnip)]₂(Mo₆O₁₉) (1), Cu^I₄(bnib)₃(β-Mo₈O₂₆)(H₂O) (2) and [Cu^I(bnih)]₂(Mo₆O₁₉)·H₂O (3) [bnip = 1,3-bis(4-nitro-1H-imidazol-1-yl)propane, bnib = 1,4-bis(4-nitro-1H-imidazol-1-yl)butane, and bnih = 1,6-bis(4-nitro-1H-imidazol-1-yl)hexane] based on three diverse flexible ligands and isopolyoxomolybdate clusters have been successfully synthesized under solvothermal conditions at different pH values and ratio of the solvents. Their structures have been characterized by single-crystal X-ray diffraction analyses, infrared spectra (IR) and elemental analyses. For compound 1, the Cu^I ions are linked by bnip ligands to form a 2D 4⁴ cationic layer, the 2D layers are packed in offset fashions through C-H···O hydrogen bonding interactions to generate a 3D supramolecular network with 1D channels, and the isolated [Mo₆O₁₉]^2- polyanions are located in the channels. In compound 2, three bnib ligands are brigded by four Cu^I ions to form a unique unit of Cu₄(binb)₃(H₂O)₂, and the units are connected by Mo₈O₂₆^4- anions to generate an infinite 1D branched chain, which are further bridged by hydrogen bonding interactions to form a 2D supramolecular structure. In compound 3, two types of -Cu-bnih-Cu- chains are crossed each other to assemble a 3D supramolecular framework with 1D cationic channel by the hydrogen bonding interactions, and the channels are occupied by Mo₆O₁₉^2- anions. Furthermore, the thermal stabilities, power X-ray diffraction, the photoluminescent properties of compounds 1–3 and the electrochemical properties of compounds 1 and 2 have been also investigated.