Synthesis And Property Study Of Polyoxotungstates And Polyoxomolybdates Decorated By Transition Metal And Organic Amine

In our paper, three new compounds based on the building units of [α-PMo12O40]3- and [PW9O34]9? polyoxoanions respectively, which are functionalized by various transition metals and organic amines, have been synthesized under hydrothermal condition. Meanwhile, we discussed the structures of these three compounds and the synthetic conditions and rules. These three compounds were characterized by the single-crystal X-ray diffraction, elemental analysis, IR spectra, TG analysis and a magnetic study of compound 1 was carried out.1. Two sandwich-type polyoxotungstates have been synthesized and structurally characterized: [Ni₃(en)₆(H₂O)₂(P₂W₁₈Ni_O70][Ni(en)₂]₂·16H₂O 1 {Ni₂(en)₄(H₂O)₂[P₂W₁₈Ni₄(en)₂O₆₈]}[Ni(en)₂(H₂O)₂][Ni(en)₂]·14H₂O 2 Two new extended sandwich-type polyoxometalates have been successfully synthesized using an in-situ synthesis method under hydrothermal condition. Although the same initial reactants and the similar synthesis were used for preparing compounds 1 and 2, there existed a huge difference in the structures of compounds 1 and 2. Compound 1 is a sandwich-type polyoxometalates, sandwiching a central symmetric rhomb-like [Ni4O16] segment. It exhibits an interesting 1D wavy-looking inorganic-organic hybrid chain based on the same terminal oxygen atom of two adjacent [Ni₃(en)₆(H₂O)₂(P₂W₁₈Ni₄O₇₀)]^4-and Ni atoms. However, compound 2 shows a 0D structure. In addition, the magnetic susceptibility of compound 1 was investigated and the magnetic property of compound 1 indicates dominant intramolecular ferromagnetic interactions.2. A new 3D supramolecular network structure constructed from classical [α-PMo12O40]3- polyoxoanion and organic ligand dafo has been successfully obtained under hydrothermal condition: [Cu(dafo)₃]₂[Cu(dafo)₂(H₂O)₂][α-PMo₁₂O₄₀]2·4H)2O 3In compound 3, there are extensive hydrogen bonding interactions among the copper organonitrogen complex units, the terminal oxygen atoms of the Keggin [α-PMo₁₂O₄₀]^3-polyoxoanions, the coordinated water molecules and the guest water molecules, extending the discrete molecules into a 3D supramolecular framework.