Syntheses, structures and properties of two 2-D layered hybrid organic-inorganic materials based on different V₄O₁₂ building units

Two new layered hybrid organic-inorganic compounds [Zn(pyim)] ₂V₄O₁₂ (1) (pyim = 2-(2-pyridyl)imidazole) and [Cu(bim)₂]₂V₄O₁₂(H ₂O)·CH₃CH₂OH (2) (bim = bis(1-imidazolyl)methane) based on polyoxovanadates (POVs) and organic ligands decorated transition metal units have been synthesized by hydrothermal and solvothermal methods respectively. Single crystal XRD, fluorescence spectrum, magnetic measurement, IR spectra, powder XRD and thermogravimetric (TG) measurements were performed to analyze the structures and properties of 1 and 2. The structural analysis reveals that compound 1 features a two-dimensional {[Zn(pyim)]₂V₄O₁₂}_n layered structure, constructed by sine wave-like {V₄O₁₂} _n^4n- chains, Zn²⁺ ions and pyim ligands. In the layered structure of 2, {V₄O₁₂}^4- circles are connected by Cu²⁺ ions to form {Cu(V₄O₁₂)} _n^2n- chains, which are further linked by {Cu(bim) ₄}²⁺ subunits to generate a hybrid layer of 2. The magnetic susceptibility measurement indicates strong antiferromagnetic interactions between Cu²⁺ ions in 2.