Wenqi Zhao

Assembly of six [HxAs2Mo6O26](6−x)− cluster-based hybrid materials from 1D chains to 3D framework with multiple Cu–N complexes

A series of organic–inorganic hybrid compounds, [{Cu(4,4′-bipy)1.5(H2O)2}2{H2As2Mo6O26}] (1), [{Cu (biim)2}2{HAs2Mo6O26}{Cu(biim)Cl}]·H2O (2), (H2bib)[{Cu(H2O)2(bib)}{H2As2Mo6O26}]·2H2O (3), [{(Hbix)Cu(bix)0.5}2{As2Mo6O26}]·2H2O (4), [{Cu(bmb)1.5(H2O)}2{H2As2Mo6O26}]·2H2O (5), 0 and [{Cu2(bth)4}{H2As2Mo6O26}]·H2O (6) (4,4′-bipy = 4,4′-bipyridine; biim = biimidazole; bib = 1,4-bis(1-imidazolyl)benzene; bix = 1,4-bis(imidazol-1-ylmethyl)benzene; bmb = 1,4-bis(benzimidazol-1-yl)benzene; bth = 1,6-bis(1,2,4-triazol-lyl)hexane), were hydro-thermally synthesized and structurally characterized via elemental analysis, TG, IR, XPS, XRD, and single-crystal X-ray diffraction. The crystal structures 1–6 are formed by metal–organic complexes and the [HxAs2Mo6O26](6−x)− cluster. Compounds 1–2 feature infinite 1D-chain structures. Compounds 3–5 form 2D-layer structures in which Cu cations are five-, six-coordinated with polyoxoanions and organic ligands. Notably, compound 6 introduces the POM system into a metal–organic framework (MOF) to form a unique POMOF {42·611·82}{42·64}{44·69·7·8} topological structure. The coordination modes of the [HxAs2Mo6O26](6−x)− cluster in compounds 2, 5 and 6 are reported for the first time. The photocatalytic properties of 1–6 are studied for the decomposition of methylene blue (MB) under UV light. In addition, all the compounds exhibit good electrocatalytic performances for the reduction of nitrite.

A new 3D POMOF with two channels consisting of Wells–Dawson arsenotungstate and {Cl4Cu10(pz)11} complexes: synthesis, crystal structure, and properties

Herein, a new 3D POMOF [{Cl4Cu10(pz)11}{As2W18O62}]·1.5H2O (pz = pyrazine) (1) has been synthesized using a hydrothermal reaction, and characterized by single-crystal X-ray diffraction analysis, elemental analysis, IR, TG, and UV-vis-NIR spectroscopy, XPS, BET analysis and XRD. Single crystal X-ray analysis reveals that compound 1 consists of the classical Wells–Dawson [As2W18O62]6− polyoxoanion and {Cl4Cu10(pz)11} complexes. Compound 1 possesses two different channels which form a 3D topology framework with the Schlafli symbol of {3·4·56·67}2{3·46·53}2{32·42·56·65}. Additionally, compound 1 shows photoluminescence properties and excellent photocatalytic activity for the degradation of RhB dye under UV irradiation. The photocatalytic reaction kinetics and mechanism have been also investigated.

Synthesis and photo-/electro-catalytic properties of a 3-D supramolecular framework based on [HxAs2Mo6O26](6−x)− and {Cu-diz} complexes

Abstract Herein, an arsenomolybdate, {Cu(diz)4(H2O)2}[{Cu(diz)2(H2O)2}2{As2Mo6O26}]·2H2O (diz = 1,2-diazole) (1), has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, IR, TG, XPS, PXRD, and UV–Vis-NIR. The {Cu-diz} complexes link the [As2Mo6O26]6− polyoxoanions, forming a 1-D infinite chain. The 2-D layer is constructed from 1-D chains through hydrogen bonds. Adjacent layers and free {Cu(diz)4(H2O)2} complexes are fused through hydrogen bonding to form a 3-D topological framework with symbol of {414·610·84}{4}2. Compound 1 exhibits luminescence at room temperature, excellent degradation activity for four different organic dyes (RhB, MB, MO, and AP) under UV irradiation. The photocatalytic mechanism of 1 is discussed in detail. Furthermore, the electrocatalytic activity of 1 toward hydrogen peroxide has also been studied.

An unprecedented 3-D supramolecular framework of {CuCN} coordination polymer based on anhydride: in situ formation of ligand by intramolecular dehydration

Abstract Hydrothermal reactions of K4[Fe(CN)6]∙3H2O with H2bimdc (H2bimdc = benzimidazole-5,6-dicarboxylic acid) afforded a coordination polymer (CP), [Cu(CN)(bimdca)] (1) (bimdca = benzimidazole-5,6-dicarboxylic anhydride), as the first example of the {CuCN}-based CP modified by anhydride. The polymer is characterized by elemental analysis, IR, TG, XRD, and single-crystal X-ray diffraction. In 1, horizontal and vertical parallel chains based on {Cu2(CN)4(bimdca)2} dimer units crisscross resulting in a 2-D network with a (4462) topology, which is further connected to adjacent 2-D layers generating a 3-D supramolecular framework through intermolecular force between oxygens of anhydride. In addition, 1 exhibits interesting fluorescence and good degradation ability for MB under UV light. Graphical Abstract