Tingting Yu

Structure and bifunctional electrocatalytic activity of a novel 3D framework based on dimeric monocopper-substituted polyoxoanions as ten-connected linkages

A unique hybrid compound with dimeric monocopper-substituted Keggin polyoxoanions as ten-connected linkages, [Cu5(en)9][(PW11CuO39)2]·18H2O (1) (en = ethylenediamine), has been synthesized and characterized by elemental analysis, IR, TG analysis, powder X-ray diffraction and single-crystal X-ray diffraction. In 1, each dimeric Keggin [PW11CuO39]210− cluster as an unusual deca-dentate connector links ten [Cu(en)2]2+ complexes to form a three-dimensional (3D) framework with a (44·832·129) topology. The successful synthesis of 1 provides a feasible route for us to design and prepare high-connectivity and high-dimensionality hybrid compounds with the dimeric substituted polyoxoanions as linkages. Furthermore, the electrochemical studies have shown that 1 has bifunctional electrocatalytic activity towards not only the reduction of normal inorganic molecules hydrogen peroxide (H2O2) and potassium iodate (KIO3) ascribed to the W-centers in [PW11CuO39]210−, but also the oxidation of biologic molecules ascorbic acid (AA) and dopamine (DA) ascribed to the Cu-centers in [Cu5(en)9][(PW11CuO39)2]·18H2O.

Assembly of co-bimb-polyoxotungstate hybrids: from 1D chain to 3D framework influenced by the charge of Keggin anions

Two new inorganic–organic hybrid compounds: [Co(H2O)2(bimb)2]2[SiW12O40] (1) and [Co2(H2O)(bimb)4](HBW12O40)·H2O (2) (bimb = 1,3-bis(1-imidazoly)benzene), have been synthesized under the same hydrothermal conditions and characterized by single crystal X-ray diffraction, IR spectra, elemental analyses and powder X-ray diffraction. Structural analyses show that 1 displays a 1D polymeric chain, whereas 2 presents a complicated 3D self-penetrating framework. The distinct structural features of the two compounds suggest that the charge of the Keggin anions should play a significant role in the process of assembly. The electrochemical properties of 1 and 2 were investigated in detail.

Tuning the dimension of POM-based inorganic–organic hybrids from 3D self-penetrating framework to 1D poly-pendant chain via changing POM clusters and introducing secondary spacers

Through tuning the different polyoxometalate (POM) clusters and the secondary spacers, four new various dimensionality inorganic–organic hybrid compounds Cu5(pzta)6(H2O)2[Mo8O26] (1), Cu5(pzta)6(H2O)6[PW12O40]·(OH) (2), Cu4(pzta)2(bipy)(H2O)4(OH)2[Mo8O26]·2H2O (3) and [Cu2(pzta)2(bipy)2(H2O)2][HPW12O40]·8H2O (4) (pzta = 5-(2-pyrazinyl)tetrazole, bipy = 4,4′-bipyridine) have been synthesized under identical hydrothermal conditions. The four compounds were assembled from copper cations, N-donor ligands and POM clusters. Compound 1 displays a novel self-penetrating 3D framework. When the POM clusters were changed from β-[Mo8O26]4− (β-Mo8) to [PW12O40]3− (PW12), compound 2 was obtained, which is a 2D layer with square channels into which the tetradentate PW12 anions as templates are incorporated. Furthermore, by introducing second spacer bipy into the reaction system of 1 and 2, respectively, compounds 3 and 4 were obtained. 3 shows a 2D layer that consists of adjacent metal–organic chains fused together by six-connected β-Mo8 anions, and 4 exhibits a 1D poly-pendant chain constructed by dinuclear copper complexes and PW12 clusters. The distinct structural features of the four compounds suggest that different POM clusters and secondary spacers should have great effect on the structures of POM-based inorganic–organic hybrids. Additionally, the luminescent and electrochemical properties for 1–4 have been investigated.

Two novel zipper-like compounds of the usual and bivanadyl capped Keggin clusters connected by propeller-shaped complexes

By choosing asymmetric L ligands (L = 1-(imidazol-1-yl)-4-(1,2,4-triazol-1-ylmethyl)benzene), Cu2+/Co2+ cations and Keggin clusters as starting materials, two new POM-based zipper-like compounds, {Cu(L)4[HPMo12O40]}·4H2O (1) and {[Co(L)4][HPMo8VV4O40(VIVO)2]} (2), have been hydrothermally synthesized and characterized by elemental analyses, single-crystal X-ray diffraction, XPS, powder X-ray diffraction, IR spectroscopy, and TG analyses. A structural feature of 1 and 2 is that there exists a 1D + 1D → 3D interdigitated architecture achieved using molecular zippers, in which overhanging mono-coordinated L arms act as teeth. Compound 2 shows bifunctional electrocatalytic activities toward not only reduction of normal iodated inorganic molecules (IO3−) ascribed to Mo-centers, but also oxidation of biological molecules such as ascorbic acid (AA) ascribed to V-centers.

Synthesis and structural characterization of 3d–4f heterometallic coordination polymers: from cluster to chain

Two new 3d–4f heterometallic coordination polymers, [MnIV2CeIV3O6Na(OAc)8(H2O)5](OH)·10H2O (1) and [MnIINdIII2Na2(OAc)8(H2O)6]·2(OH) (2) (OAc− = acetate), have been conventionally synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. In 1, three Ce4+ and two Mn4+ cations are bridged by OAc− and μ3-O2− bridges forming a pentanuclear 3d–4f heterometallic [MnIV2CeIV3O6(OAc)8(H2O)5] cluster, while in 2, two Nd3+ and one Mn2+ cations are linked by carboxylic bridge of OAc− anions giving a 1D 3d–4f heterometallic [MnIINdIII2(OAc)8(H2O)6] chain. Additionally, pentanuclear heterometallic [MnIV2CeIV3O6(OAc)8(H2O)5] clusters in 1 are further connected by Na+ cations to result in a 1D chain, whereas the 3d–4f heterometallic chains in 2 are linked by Na1–O–Na1 dimers into a 2D array. Moreover, the variable magnetic susceptibilities of 1 and 2 are investigated.

Assembly of two new polyoxometalate-templated supramolecular compounds by utilizing flexible 1,4-bis(pyrazol-1-ylmethyl)benzene ligand

Two new polyoxometalate-templated supramolecular compounds, [CuI4(bpmb)4][PMoVI11MoVO40] (1) and [CuI4(bpmb)4SiW12O40] (2) (bpmb = 1,4-bis(pyrazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by routine methods. Structural analysis shows that in 1, there exist crown-like [CuI4(bpmb)4] coordination macrocycles, and the Keggin polyanions [PMo VI11MoVO40]4− (abbr. as PMo12), which direct the crown-like macrocycle to form a 3-D supramolecular framework. In 2, there exist unusual meso-helix chains, and these chains are mutually interlaced in a wave–trough pattern, but without intersection resulting in a multi-cavity layer, in which the [SiW12O40]4− (abbr. as SiW12) clusters as guest molecules occupy the cavities of the layers. The distinct structural features of the two compounds suggest that Keggin polyanions should play a significant role in the process of assembly. Electrocatalytic properties of 1 and 2 were investigated. Graphical Abstract Two new POM-templated supramolecular compounds with good electrocatalytic activities toward reduction of iodate have been obtained, which shows that Keggin anions should play a significant role in the process of assembly.

A molecular crown analogue templated by Keggin polyanions: synthesis, structure, and electrochemical and luminescent properties

Abstract A hybrid compound, [CuI4(bpmb)4][PWVI11WVO40] (1) (bpmb = 1,4-bis(pyrazol-1-ylmethyl)benzene), has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis, infrared spectroscopy, elemental analyses and powder X-ray diffraction. In compound 1 crown-like [Cu4(bpmb)4]4+ macrocycles templated by Keggin-type [PWVI11WVO40]4− polyanions (abbreviated PW12) exist. Supramolecular layers are formed by intermolecular hydrogen bonding interactions of discrete crown-like [Cu4(bpmb)4]4+ macrocycles and [PWVI11WVO40]4− polyanions. The electrochemical and luminescence properties of compound 1 were investigated.