Syntheses, Crystal Structure And Properties Of Transition-metal Substituted Polyoxometalates Based On Arsenic Heteroatom

In the paper, on the basis of molecular design and assembly conceptions, adopting simplematerials such as Na₂WO₄·2H2_O, NaAsO₂, Na3AsO4, Na₂MoO₄·2H2_O and Na2HPO4·12H2_O underhydrothermal conditions or the conventional aqueous methods, several of novel organic-inorganicpolyoxometalates derivatives based on arsenomolybdates or arsenotungstates were obtained bycontroling reaction conditions such as pH value, temperature, time, concentration and reactantstoichiometry. These complexes were charactered by X-ray crystallography, IR, UV spectroscopy,thermal properties, photocatalytic analysis, XRD、EDX or magnetic analyses.1. Two novel hexa-TM sandwich-type arsenotungstates compounds based on the trivacantKeggin-type [B-α-AsW]₉9O₃3and the unprecedented [As124W6O34]fragments:[Zn（Hen）]6[B-α-AsW₉O₃3]2·6H2_O （1） and [Ca（H2_O）5]4{[Ca（H2_O）]6Cl}[H5As4W6O34]2·nH2_O （2）were sysnthesized successfully through hydrothermal synthesis method or the conventionalaqueous methods. Compound2shows an infinitely extended2-D network.2. One arsenotungstates based on the {As2W8O31} fragment H8（en）3.5[As2W8O31]·6H2_O （3） andtwo tri/tetra-TM sandwich-type arsenotungstates based on the trivacant Keggin-type[B-α-AsW₉O₃4]9or [B-β-AsW8O31]9building block: Na0.5（H2en）6.5{Ni3（en）[B-α-AsW9O34][B-β-AsW₈O₃1]}Cl1.5·9H2_O （4） and [H2en]₄{[Ni₄（Hen）₂][B-α-AsW₉O-34]2}·5H2_O （5） weresysnthesized successfully under the conventional aqueous methods.3. Two novel organic-inorganic arsenomolybdates based on the dicapped-Anderson type[（MO6）Mo6O18（As3O3）2]4fragments:[（NiO₆）Mo₆O₁8（As₃O₃）2]Cl₂·6H2_O （6） and [Zn（en）（H2_O）]2[（ZnO6）（As3O3）Mo6O18]（7） were sysnthesized through hydrothermal synthesis method or theconventional aqueous methods. The neighboring units of6are combined together via the hydrogenbonding interactions forming a3D supramolecular framework.4. A series of phosphomolybdates based on the Strandberg-type [P6–2Mo5O23]fragment（H₂en）2[Cu（en）（H2_O）Cu（en）（H2_O）3][P₂Mo₅O₂3]·5.5H2_O（8）,（H₂en）2[Zn（H2_O）4][P₂Mo₅O₂3]·3H2_O（9）,（H2en）3[Mn（H2_O）4][Mn（H2_O）3]2[P₂Mo₅O₂3]₂·14.5H2_O （10） and （H₂en）₂[Ag₂（P₂Mo₅O23）]·2H2_O （11） have been successfully synthesized by the conventional aqueous solution method.8represents a novel1D chain-structure containing a rare binuclear Cu（II） cluster,9stands for the first1-D chain-like structure constructed from the Strandberg-type clusters andZn²⁺ bridges. Both10and11show first2D sheet networks built by [P2Mo5O23]^6–fragmentsbridged by Mn²⁺ and Ag⁺cations.