The Synthesis, Structure And Electrocatalytic Properties Research Of Phosphotungstate Modified By Metal And Organic Amine Ligand

Under hydrothermal conditions utilizing precursor synthesis, we obtain threeof metal, organic amine modified Keggin type phosphotungstate hybridcompounds:[Co2(H2O)4(bimb)4][PWVWVI11O40](bimb=1,3-bis(1-imidazoly)benzene)(1)[Zn3(H2O)4(bimb)4][PWV3WVI9O40](bimb=1,3-bis(1-imidazoly)benzene)(2)[Cu2(4,4’-bpy)3][HPW12O40](4,4’-bpy=4,4’-bpyridine)(3)Elemental analysis, IR, X-ray single crystal diffraction, powder X-raydiffraction and photoelectron spectroscopy of the three compounds werecharacterized. The results show that there is a two-dimensional layered structureby π···π role of bimb molecules between the rings in compound1. An interestingstructural feature of2is that an intricate3D framework can be described in threesteps: Firstly, on the one hand, two Zn1cations are linked by two bimb ligands toform a [Zn(bimb)]24+molecule ring while a Zn2cation is linked by two bimbligands to achieve a [Zn(bimb)2]2+coordination fragment. The [Zn(bimb)]24+molecule rings and [Zn(bimb)2]2+coordination fragments are further connectedtogether via Zn1-N4bonds, forming a1D Zn-bimb coordination cation chain. Onthe other hand, each PW126-cluster links two Zn2ions via its two oppositeterminal oxygen atoms while each Zn2ion links two PW126-clusters, as a result, a1D anion chain is formed. In the second step, the above cation and anion chainsare fused together via sharing the Zn2cations to complete a2D layer. In the thirdstep, among these2D layers, each of the PW126-cluster is further linked by twoZn12+cations of molecule rings respectively from two adjacent2D layers. The3D framework is ultimately formed by these connections. And there is a triple interpenetrating organic-inorganic hybrids acid groups formed through rigidlinear ligand of4,4’-bpy in compound3.By changing synthetic materials, the influence of transition metal ions anddifferent kinds of ligands on compound structure is researched. These threecompounds reveal certain rules: in compound1and2, by fixing phosphotungstateand V type ligands and changing different metal ions (Co, Zn), we obtainedcompounds of two different dimensions. These facts illustrate that different metalcoordination geometry have important influences on the structure ofphosphotungstate-based compound. By changing the ligand bimb as4,4’-bpy, weobtained compound3, which having a triple interpenetrating structure. The linearbridging ligand with longer space is easier to obtain a complex interpenetratingnetwork structure in synthesizing phosphotungstate-based compound. Further, theelectrocatalytic experiments of the compounds were carried out. The results showthat compound1has a sensitive response to H2O2and its electro-catalytic effectis ideal.