| In this paper, we synthetized a series of hybrid TMSPs based on the lacunaryPOMs fragments, which can act as structure-directing agents to induce thetransition metals to form a custer aggregations under hydrothermal conditions. Wefinally obtained five new compounds through controling reaction conditions such asconcentration and reactant stoichiometry, temperature, time, pH value and so on.These complexes were charactered by single-crystal X-ray diffraction analyses,elemental analyses, IR, PXRD analyses, UV-vis spectroscopy and photoluminescentproperty. At last, we preliminarily studied the photocatalytic activity of thesecatalysts for methylene blue degradation under visible-light irradiation.A new sandwiched polyoxometalate [HK11Cd4Cl2(PW9O34)2]·18H2O （1）, basedon two trivacant Keggin-type {PW9O34} clusters was obtained through hydrothermalsynthesis method and the conventional aqueous methods. Crystal data: monoclinicsystem, C2/c space group; a=19.2997（4）（?）, b=13.8014（3）（?）, c=31.9819（8）（?）; β=102.764（2）°; V=8308.3（3）（?）3; Z=4; R1=0.0378, wR2=0.0989.The characteristic bands in the solid photoluminescence spectra and UV-visspectra can be assigned to the charge transfer of O→W in the [B-α-PW9O34]9–polyoxoanion, and the plot of the Kubelka–Munk function F against E shows theband gap of1can be assessed at3.25eV.Two new compounds based on {AsMo12O40} clusters and {AsW12O40} clusterswere sysnthesized successfully through hydrothermal synthesis method. The crystaldata for {[Cu（2,2’-bipy）2]2Cl}[AsMo12O40]（2）: triclinic system, P-1space group; a=12.6462（3）（?）, b=14.5837（3）（?）, c=18.1193（4）（?）; α=96.8346（19）, β=96.9577（19）, γ=100.995（2）°; V=3221.40（13）（?）3; Z=2; R1=0.0343, wR2=0.086.For [Fe8O6（2,2’-bipy）8（H2O）8（AsO4）2][AsW12O40] H2O （3）: monoclinic system,C2/m space group; a=16.4304（2）（?）, b=20.1267（4）（?）, c=18.8428（3）（?）; β=95.7989（14）°; V=6199.20（18）（?）3; Z=2; R1=0.0540, wR2=0.1353.The emission bands for2and3are assigned to the intraligand π*–π transitionof the2,2’-bipy ligand. In addition, the two compounds showed high photocatalyticeffciency（52.1%and89.9%, respectively） for the degradation of MB in aqueoussolution under xenon arc lamp irradiation. After photocatalytic activities, thepowder X-ray diffraction patterns for compound2and3are in good agreement withthe ones simulated based on the data of the single-crystal structures, which indicatesthe stability of the structures.Two new TMSPs based on single lacunary POT fragments,{[Cu（deta）（H2O）2]2[Cu（deta）（H2O）][α-SiCuW11O39]}·5H2O （4） and [Ni（en）2][Ni6（μ3-OH）3（H2O）6（en）3 (B-α-SiW9O34)]2·3H2O （5）, were sysnthesized under hydrothermal conditions.Crystal data for4: monoclinic system, P21/n space group; a=11.08313（17）, b=22.8430（5）, c=22.4297（4）; β=98.4231（16）°; V=5617.31（17）3; Z=4; R1=0.0613, wR2=0.1335. Crystal data for5: monoclinic system, P21/n space group; a=12.88531（11）, b=23.4526（2）, c=31.9819（8）; β=101.8760（9）°; V=5011.09（8）3; Z=2; R1=0.0348, wR2=0.1207.Solid-state fluorescence spectra (λem=nm) of compound4can beattributed to the charge transfer of O→W in the [SiCuW11O39]6-polyoxoanion,while in compound5, the vacancy sites of the {SiW9O34} clusters were replaced by{Ni6} clusters, and the mobility of the charge on the {SiW9O34} clusters isincreasing, which are in favor of generating the fluorescence phenomenon(λem=468nm). The same to2and3,4and5also showed high photocatalyticefficiency（90.7%and94.1%, respectively） for the degradation of MB in aqueoussolution under xenon arc lamp irradiation, and both of the structures are stable. |
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