Syntheses, Structures And Properties Of Polyoxotungstate Based Manganese And Rare-earth

Polyoxometalates can act as a class of uniqe inorganic multidentate O-donor ligands to trap transition metal or rare earth forming novel aggregates with excellent properties resulting from its unique molecular structure and the variety of electronic structure. In this paper, on the basis of molecular design and self-assembly, we obtained ten compounds under conventional solution conditions. Mainly, it contains two parts:the first part includes three compounds, and the obtaining of these three manganese-substituted silicotungstate largely stimulated by the multiple valence of manganese and a large uniaxial anisotropy deriving from the presence of the Jahn-Teller distorted MnⅢ ions. The second part present seven inorganic-organic hybrid rare-earth-substituted polyoxotungstates. All the above-mentioned compounds were fully characterized by elemental analyses, single-crystal X-ray diffraction, IR spectroscopy, UV spectroscopy and thermogravimetric analyses. Moreover, the magnetic research, electrochemical property and catalytic were also investigated for some compounds.I. Three manganese-substituted silicotungstate K9[H14{SiWi0MnⅡMnⅢO38}3(CO3)]·39H2O (1) has been firstly isolated. The compound 1 represent the first Mn-substituted silicotungstate trimer in which CO32- resides inside the three keggin{SiW1oMnⅡMnⅢO38} units with its three O atoms participating in the coordination and the magnetic investigation indicates that 1 exhibits the antiferromagnetic coupling. In addition, the polyoxoanion of 1 linked by potassium cations to generate the 3D architecture. The compound K2H(CN3H6)9[Mn3(H2O){SiW9O34}{SiW8O31}]·11H2O (2) contains two asymmetry subunits {SiW9O34}10- and{SiW8O31}10-, and Cs4H8[{Mn(H2O)2}{W11O38H2}2]·42H2O (3) is a sandwich-type compound.Ⅱ Four novel rare-earth-substituted organic-inorganic hybrid selenotungstates CsNa2H15[{La3(H2O)11[Se2W22O76(gly)2]}2(Se2W7O30H2)]·24H2O (4), CsNa2H15[{Ce3(H20)11[Se2W22076(gly)2]}2(Se2W703oH2)]·34H2O (5) Cs2Na4H,2[{Pr3(H20)10[Se2W22076(gly)2]}2(Se2W703oH2)]（20H20 (6) Cs2Na4H12[{Nd3(H2O)10[Se2W22O76(gly)2]}2(Se2W7O30H2)]·20H2O (7) and three rare-earth-substituted hybrid isopolytungstates CsNaH4[Pr(H2O)3(gly)]2[Pr(H2O)6(gly)]2[W22O74H2]·12H2O (8), CsNaH4[Nd(H2O)3(gly)]2[Nd(H2O)6(gly)]2[W22O74H2]·12H2O (9), CsNaH4[Sm(H2O)3(gly)]2[Sm(H2O)6(gly)]2[W22O74H2]·12H2O (10) have been isolated by "one-pot" method.