New assembly of organic components and transition metal complexes based on [VMo6O22]3− and [V2Mo6O26]6− building blocks: syntheses, crystal structures, and magnetic properties

Two new molybdovanadates, (H3NCH2CH2NH3)3 [Mo6VO22(CH3COO)3]·5H2O (1) and (H3NCH2CH2NH3)2{(Mo6V2O26)[Cu(NH2CH2CH2NH2)(H2O)2]}·4H2O (2), have been synthesized in aqueous solution and characterized by IR, UV–vis, single-crystal X-ray diffraction, thermal gravimetric, elemental analysis, and magnetic analysis. Compound 1 is a crown-shaped ring consisted of six edge-sharing MoO6 octahedra linked to a central {VO4} unit. The MoO6 octahedra are in pairs connected with the carboxylato ligands from three acetic acid molecules. Compound 1 is the first example of a molybdovanadate coordinated by acetic acid molecules. In addition, multipoint hydrogen-bonding interactions exist in 1, which bridge the crown-shaped [Mo6VO22 (CH3COO)3]6− clusters and the protonated ethylenediamine molecules into three-dimensional (3D) networks. The structural feature of compound 2 is the formation of one-dimensional (1D) zip-zag chain in which [Mo6V2O26]6− clusters are covalently bonded to copper coordination groups through the terminal oxygen of the {VO4} tetrahedron. The magnetic investigation on compound 2 demonstrates the possible occurrence of antiferromagnetic interactions by intermolecular linkage.