| Basket type {P6Mo18O73} is a nonclassical mixed valence polyoxometallates(POMs). Owing to the larger steric hindrance of basket POM and the instability of their intermediate in the solution, the compounds are difficult to isolate from solution. As a result, the numbers of basket-liked POM are still limited so far, and most of them are zero dimensional clusters. On the other hand, Dawson-type arsenic molybdenum are more unstable. These compounds are difficult to be prepared by precursor method or one step synthesis. Only three 0-D Dawson-type arsenic molybdenum are reported for their large steric hindrance. In this paper, basket-liked POMs are successful extended from 0-D clusters to 1-D and 2-D layer for the first time, which lead 16 kinds of basket-POM with 0-D, 1-D, and 2-D structure. These compounds are difficult to be prepared by precursor method or one step synthesis. In this paper, basket-liked POMs are successful extended from 0-D clusters to 1-D and 2-D layer for the first time, which lead 16 kinds of basket-POM with 0-D, 1-D, and 2-D structure. via ynergistic effect between flexible ligands and(NH4)6Mo7O24·H2O, and template effect of alkaline earth metal ions. Through adjusting the p H of the solution, the kind of imidazole ligands, as well as the reactants and the reaction temperature, As3+ as cap are introduced into Dawson cluster, which make stability of arsenic molybdenum increase. On this basis, we use small nitrogen-containing ligands to extend {As2Mo18} from 0-D cluster to 3-D network,which lead 12 kinds of non-classical Dawson-type molybdenum complexes with novel structure and excellent performance. Chemical formula of the compounds were Determined by elemental analysis and x-ray diffraction analysis, [{Zn(H2O)0.5} {Sr?P6Mo2VMo16VIO73}]·5.5H2O(1),(H2bih)3[{Fe II(H2O)2}{Sr?P6Mo2V Mo16VIO73}]·2H2O(2),(H2bih)3[{CoII(H2O)2}{Sr?P6Mo2VMo16VIO73}]·2H2O(3),(H2bih)3[{Ni II(H2O)2}{Sr?P6 Mo2VMo16VIO73}]·2H2O(4),(H2bib)3[{FeII(H2O)2}{Sr?P6Mo2V Mo16VIO73}]·4H2O(5),(H2bib)3[{CoII(H2O)2}{Sr?P6Mo2VMo16VIO73}]·4H2O(6),(H2bib)3[{Ni II(H2O)2}{Sr?P6 Mo2VMo16VIO73}]·4H2O(7),(H2bib)3[{CuII(H2O)2}{Sr?P6Mo2V Mo16VIO73}]·4H2O(8),(H2bib)3[{ZnII(H2O)2}{Sr?P6Mo2VMo16VIO73}]·4H2O(9),(H2bih)3 [{Cu II(H2O)2}{Ca? P6Mo2VMo16VIO73}]·2H2O(10),(H2bib)3[{FeII(H2O)2}{Ca?P6Mo2V Mo16VIO73}]·4H2O(11),(H4bth)[{Cu(H2O)}2{Sr?P6Mo2VMo16VIO73}]·4H2O(12),(H4bth)[{Mn2(H2O)3} {Sr?P6Mo2VMo16VIO73}]·3H2O(13), [{Cu II(H2O)2}{Ca4(H2O)4(HO0.5)3(en)2}{Ca?P6 Mo4VMo14VIO73}]·7H2O(14),(H4bth)[{FeII(H2O)}{Ca?P6Mo18VIO73}]·4H2O(15),(H2bih)(H3bih) [{Mn4Cl4(Cl O4)(H2O)6}{Mn(H2O)2}2{Ba?P6Mo18O73}2]·7H2O(16), Cu(2,2'-bpy)2{[Cu(2,2'-bpy)]3(As2Mo2VMo16VI18O62)}·4H2O(17), [H2(4,4'-bpy)]0.5[H(4,4'-bpy)]2(AsIIIAs2VMo18VI O62)·5H2O(18),(bpy)(imi)4(As2IIIAs2VMo18VIO62)·3H2O(19),(As3IIIAs2VMo18VI O62)·4H2O(20),(H2bpy)0.5(Hbpy)2[AsIIIAs2VMo15O56{Mn Cl(H2O)}3]·2H2O(21),(H2bpy)0.5(Hbpy)2 [AsIII As2VMo15O56{Fe Cl(H2O)}3]·2H2O(22),(H2bpy)0.5(Hbpy)2[AsIIIAs2VMo15O56{Co Cl(H2O)}3]·2H2O(23),(H2bpy)0.5(Hbpy)2[AsIIIAs2VMo15O56 {Ni Cl(H2O)}3]·2H2O(24),(H2bpy)0.5(Hbpy)2[AsIIIAs2VMo15O56{Zn Cl(H2O)}3]·2H2O(25), [{CuI(trz)2}7{AsIIIAsV MoV3MoVI15O62}]·2H2O(26),(Himi)(imi)3[{Cu(imi)2}4{Na(imi)2}2{As1.5IIIAs2VMo2VMo16 VI O62}2]·4H2O(27), [{Cu10(py)11 Cl4}{AsIIIAsV2Mo3VMo15VI O62}]·H2O(28), which have received the number of new compounds from Cambridge database. The compounds have been structurally characterized by IR, UV-vis spectroscopy, XRD, and XPS spectrum. The thermal stability of the compounds were studied by differential thermal analysis method.Electrochemical studies show that: in the compounds, there exist reversible redox peaks, which ascribed to consecutive one- or two-electrom processes of Mo center of {P6Mo18O73}/{As2Mo18O62}. Compound 1-9 display bifunctional electrocatalytic activities toward not only reduction of toxic inorganic molecules NO2-, but also oxidation of biological molecules AA.The diffuse reflectivity spectrum shows that the band gap of 1-28 can be assessed in the range of 2.75-3.28 e V, which can be regarded as a wide gap semiconductor material. Thus, compounds 1-28 would be potential photocatalyst. The compounds as photocatalysts exhibit universal high-efficient degradation ability for typically dyes such as MB, MO, AP, and Rh B. The highest degradation rate is up to 98.9%. And compared with other classic POMs, the compounds has higher catalytic efficiency, shorter time, longer lifetime, easy recovery, and recycling to use.The experimental results indicate that the high-dimensional basket POM 14 modified by metal complexes and three-dimensional high-connected arsenomolybdate 28 show higher catalytic degradation rate. The main reason is that these compounds have large surface area, and conjugated organic ligand in metal complexes play a very good role in Proton translocation. Catalytic reaction mechanism study found that basket-based heteropoly blue may be better synergistically catalyze than other classical POM ion or the special structure of basket-liked POM makes electron and hole migrate to the surface of basket cage rapidly. Thus the photocatalytic activities improved significantly. |
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