Yuchao Wang

Multidimensional frameworks constructed from Keggin-type heteropoly blue of molybdenum–tungsten cluster

The reaction of polyoxometalate anion [GeW11O39]8− with the complex anion [MoV2O4(H2O)2(ox)2]2− in the presence of CuCl2·2H2O and DMF (DMF = N,N-dimethyl formamide) at 85 °C in aqueous solution produces both a two-dimensional heteropoly blue H2[α-GeW10MoV2O40][Cu(DMF)3H2O]2·5H2O (1) and a three-dimensional heteropoly blue H4[α-GeW10MoV2O40]2 [CuK2(DMF)6] [K4(DMF)6] (2), which demonstrates that different molar ratio of W : Cu in the reaction could conduct different multidimensional structures of 2D and 3D. The magnetic investigation of the two compounds in temperature range from 300 K to 2 K indicated the presence of strong antiferromagnetic interactions related with the two MoV ions in these two compounds.

A 3D all-inorganic architecture based on the [H2W12O42]10− building block with different alkaline-earth metal linkers: crystal structures, surface photovoltage and photoluminescent properties

Three-dimensional (3D) all-inorganic polyoxometalate compounds, Ca2Na6[H2W12O42]·30H2O (1), Sr4H2[H2W12O42]·26H2O (2), Sr4Na2[H2W12O42]·30H2O (3) and Ba4Na2[H2W12O42]·29.5H2O (4) have been synthesized and their structures consist of [H2W12O42]10− building units and alkaline-earth metal cations (Ca2+, Sr2+ and Ba2+) as linkers. The most interesting feature is that compound 2 represents the first example of a 3D all-inorganic framework in which the paradodecatungstate-B anions [H2W12O42]10− were linked by pure alkaline-earth metal cations. Moreover, each [H2W12O42]10− building unit in compound 2 acts as a decadentate ligand coordinated with ten Sr2+ ions, which represents the highest coordination number of [H2W12O42]10− with alkaline-earth metal cations so far. Another interesting feature is that compounds 1–4 exhibit a clear response to surface photovoltage and electric field-induced surface photovoltage, which is indicative of the semiconductor property and suggests these compounds have potential applications as photocatalysts and light-to-electricity conversion materials.

The first heteropoly blue-embedded metal–organic framework: crystal structure, magnetic property and proton conductivity

The first heteropoly blue-embedded metal–organic framework (MOF) compound [Cu3(BTC)2(H2O)3]4[SiW11MoVO40](C4H12N)5·30H2O (BTC = 1,3,5-benzenetricarboxylate) has been synthesized by a one-pot hydrothermal reaction method. The heteropoly blue-based MOFs were characterized by elemental analysis, single-crystal X-ray diffraction, IR spectroscopy, diffuse reflectance UV-vis spectroscopy, magnetic measurement, and thermal gravimetric analysis. Both the diffuse reflectance UV-vis spectra and magnetic study demonstrate that the reduction state of Mo(V) was still retained in the heteropoly blue-based MOFs. The performance in humidity-dependent proton conduction of the compound was also investigated, showing enhanced proton conductivity with increasing humidity; this may find potential applications in proton conductors.

[Mn(C4H10ON)(H2O)][Fe(CN)6]: a three-dimensional cyanide-bridged ferrimagnet with a morpholine ligand.

The reaction of the Mn(II) and [Fe(CN)(6)](3-) ions in the presence of morpholine at 90 °C yields a new cyanide-bridged three-dimensional (3D) assembly, showing a ferrimagnetic ordering, frequency-dependent ac susceptibility, and hysteresis loops below 14.8 K. In addition, our feasible route to rationally design and prepare this new molecule-based ferrimagnet promises to provide new 3D cyanide-bridged complexes in the future research.

Multidimensional all-inorganic frameworks based on new molybdovanadate cluster of [VMo7O28]9− with Cu(II) linker showing semiconducting behavior

Three multi-copper molybdovanadate cluster compounds [Cu8(OH)2(H2O)2V10Mo30O132]20− (1), {[CuNa(H2O)6][Cu(H2O)4]2[Cu8(OH)2(H2O)2V9Mo30O128]}10− (2), {[Cu0.5Na0.5(H2O)3][Cu(H2O)4]2 [Cu6(OH)2(H2O)2V9Mo23O108]}9.5− (3), containing a novel [VMo7O28]9− fragment, have been isolated by using a one-pot self-assembly method. These three compounds were characterized by elemental analysis, single-crystal X-ray diffraction, IR spectroscopy, UV-vis spectroscopy, cyclic voltammetry, magnetic properties analysis, and thermal gravimetric analysis. The Z-shaped [Cu8(OH)2(H2O)2V9Mo30O128]17− anions of compound 2 can transform into the banana-shaped {Cu6(OH)2(H2O)2V9Mo23O108} units of compound 3 by only changing the pH from 4.5 to 5.0, while the introduction of nitrilotriacetic acid as an assistant ligand ensures the formation of the zero-dimensional compound 1. Magnetic studies indicate the presence of strong antiferromagnetic interactions in compounds 1–3, and the three compounds also exhibit obvious electrocatalytic activities for nitrate reduction. The semiconducting properties of these solid state compounds were revealed from the measurements of the diffuse reflectance UV-vis spectra, in which the band gap values at ca. 2.5 eV are similar to inorganic semiconductor materials, suggesting potential applications in areas of photocatalysis and light-to-electricity conversion.