Syntheses,Structures and Electrochemical Investigation of a New Dawson-based Hybrid Material with Cd-BTA Coordination Polymers

A new organic-inorganic hybrid based on tungstophosphate anions and benzotria- zole cations, [Na（BTA）E（H2O）2]2[{Cd（BTA）4（H2O）}2（P2W18O62）]·6H2O （1） （BTA = benzotriazole） has been synthesized in aqueous solution and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, and single-crystal X-ray diffraction. X-ray analysis showed that both {Na（BTA）2} and {Cd（BTA）4} units are supported on the a-Dawson polyoxoanion [P2W18062]6- via the surface bridging oxygen atoms. The electrochemical properties of 1 in aqueous solution are studied at room temperature. It was found that 1 presents good electrocatalytic activities for the reduction of NO2^-.

Proton-Conducting Polyoxometalates as Redox Electrolytes Synergistically Boosting the Performance of Self-Healing Solid-State Supercapacitors with Polyaniline

Energy storage devices with high volumetric and gravimetric capacitance are in urgent demand due to the booming market of portable and wearable electronics.Using redox-active molecules as electrolytes is a strategy to improve the capacitance and energy density of solid-state supercapacitors(SCs).In this study,polyoxometalates(POMs)are applied as proton conductors and redox mediators in polyvinyl alcohol(PVA)electrolytes,which increase the capacitance of obtained SCs with polyaniline(PANI).H_(3)PMo_(12)O_(40)-loaded PANI electrodes provide pseudocapacitance with an eight-electron Faraday reaction in a charge–discharge cycle.This has rarely been reported in SCs before.The largest capacitance of SCs with H_(3)PMo_(12)O_(40)and H_(3)PW_(12)O_(40)as electrolytes is 7.69 F/cm^(2)(3840 F/g)based on a single electrode at 0.5 mA/cm^(2).In addition,POM electrolytes exhibit excellent self-healing ability,which is attributed to the rich hydrogen-bonding network between POMs and PVA.This study demonstrates that the capacitance of solid-state SCs is improved by using molecular redox-active electrolytes and showcases the potential of applying this strategy to other energy storage devices in the future.

PIC catalysis based on polyoxometalates promoting 5-HMF oxidation in H_(2)O/MIBK biphase

Novel polyoxometalate(POM)Pickering interfacial catalyst(PIC)was fabricated through loading(NH_(4))_(5)H_(6)PMo_(4)V_(8)O_(40)(PMo_(4)V_(8))on both alkyl and alkyl-amino groups functionalized silica nanoparticles.PMo_(4)V_(8)/SiO_(2)(C_(8)/C_(8)NH_(2)with molar ratio as 1:1)PIC system provided a new catalytic model for aerobic conversion of 5-hydroxymethylfurfural(5-HMF),as well as its recovery and product separation in H_(2)O/methyl isobutyl ketone(MIBK)biphase reaction.Balancing the ratio of PMo_(4)V_(8),C_(8)and C_(8)NH_(2)gave rise to variety in hydrophilicity and hydrophobicity for PMo_(4)V_(8)/SiO_(2)(C_(8)/C_(8)NH_(2)),which enhanced the transformation of 5-HMF to 2,5-diformylfuran(DFF)in H_(2)O/MIBK with 73.7%yield at 81.8%conversion than in H_(2)O or MIBK single phase.

A series of coordination polymers constructed from flexible bis(benzimidazole)ether ligands and different carboxylates

Six new coordination polymers constructed from two structurally related ligands, 2,2′-bis(2-methylbenzimidazole) ether (L1) and 2,2′-bis(2-ethylbenzimidazole)ether (L2), have been synthesized. They are [Cu(L1)(bz)2] (1), [Cu(L2)(bz)2] (2), [Zn2(L1)(m-bdc)2] (3), [Cd2(L2)(m-bdc)2(H2O)]2·H2O (4), [Zn(L1)(OH-bdc)-(H2O)] (5) and [Zn2(L2)(btca)] (6), where Hbz = benzoic acid, m-H2bdc = 1,3-benzenedicarboxylic acid, OH-H2bdc = 5-hydroxyisophthalic acid, and H4btca = 1,2,4,5-benzenetetracarboxylic acid. In 1 and 2, the bidentate N-donor ligands (L1 and L2) bridge neighboring metal centers to form 1D single chains. The bz anions are attached on both sides of the chains. In 3 and 4, the N-donor ligands (L1 and L2) in cis conformations bridge two metal centers to generate a [M2(L1)]4+ unit (M = Zn(II) and Cd(II)). The adjacent [M2(L1)]4+ units are further linked via the dicarboxylate anions to form 1D double chain structures. In 5, the Zn(II) cations are bridged by OH-m-bdc anions to form an infinite polymeric chain. The L1 ligands are attached on one side of the chain in a monodentate mode. In 6, two Zn(II) cations are bridged by two L2 ligands to form a [ZnL2]2 4+ ring, which is further linked by btca anions to generate a 2D layer. The luminescent properties of the ligands and 3–6 in the solid state at room temperature were also studied.

Fabrication of nanoreactors based on polyoxoperoxometalates and enhancement of their catalytic activity

The nanoreactors were fabricated by reacting amphiphilic quaternary ammoniums and polyoxoperoxometalates Kn[PW12-xTix. O40-x（O2）x] （x = 1, 2 and 3; n =5, 7 and 9） （K5[PW11TiO39（O2）], KT[PWloTi2038（O2）2] and K9[PW9Ti3O37（O2）3]）. Fourier transform infrared spectroscopy （FT-IR）, transmission electron microscopy （TEM） were used to characterize the resulting samples. This kind of nanocatalysts could promote NH4SCN＇ degradation into simple inorganic compounds such as SO4^2-, HCO3^- and NO3^- only using oxygen as an oxidant under room conditions.

Stepwise Construction of Multivariate Metal–Organic Frameworks from a Predesigned Zr16 Cluster

A series of multivariate metal-organic frameworks(MOFs)with predictable topologies are stepwise constructed from a predesigned versatile hexadecnuclear zirconium cluster.The[Zr_(16)]cluster is constructed from a center classic[Zr_(6)(μ_(3)-OH)_(4)(μ_(3)-O)_(4)(COO)_(4)]cluster and two capped[Zr_(5)(μ_(3)-OH)_(4)(μ2-O)_(4)(HSQA)_(4)(DMF)_(4)](SQA=squaric acid,DMF=dimethylformamide)clusters which have 24 potential coordination sites to link metal ions and four formate groups to be substituted by other organic ligands.Based on this predesigned cluster.