| It is common knowledge that polyoxometalates ?POMs? are an intriguing class of metal-oxide clusters of nanosize with unique physical and chemical properties. Due to their fascinating structural diversity and oxygen-rich surface with strong coordination ability, POMs show potential applications in catalysis, ion exchange, medicine, gas storage, materials science, and nanotechnology. Because of its high negative charge, high stability, oxidation reducing and adjustable molecular characteristics of structure, such that it is expected to have potential developments in high proton conductor, nonlinear optics and other functional materials. At present, polyoxometalates modified chemical especially vanadium cap modifiedis still a hotspot in the field of POMs. So far, reported the Mo-V cap Keggin Structure molybdate very rare. Therefore Miscellaneous Multi molybdate, especially vanadium cap modified heteropoly molybdate more of its major significance.This article is by hydrothermal synthesis, selection of N-containing ligand and transition metal ions ?cobalt, nickel? modifications to Mo-V cap multi-metal molybdates, two unprecedented vanadium cap modified polyoxometalate-based coordination polymers have been successfully synthesized. The crystal structures were characterized by single crystal X-ray diffractions, Powder X-ray diffraction, IR spectraand, thermogravimetry?TG? analysis. [Co?bpz??Hbpz?][Co?SO4?0.5?H2O?2?bpz?]4[PMoVI8MoV4VIV4O42]·13H2O ?NENU-530? [Ni2?bpz??Hbpz?3?H2O?2][PMoVI8MoV4VIV)4O44]·8H2O ?NENU-531?Two compounds exhibit exceptional chemical and hydrothermal stability, as well asconsiderable thermal stability. And they were found stable in basic aqueous solution with different pH values ?pH= 2-12? adjusted by HC1 or NaOH at room temperature. That was few reported in POM-based polymers. The proton conductivity behaviors of both compounds were evaluated by the alternating current ?AC? impedance spectroscopy method. The excellent proton conductivity of both compounds are up to 10-3 and 10-4 S·cm-1 at 75? under 98% RH, Moreover, as the RH increased from 98% to 75% at 30?, the values of proton conductivity for both compounds rose.A novel POM-based inorganic-organic hybrid materials have been obtained by introducing metal ions and N-/O-containing ligands to the systems based on the superlacunary heteropolyanion under hydrothermal conditions.[Cu?en?2H2O]3[(a-SiW11O39)Gd?H?2O)??2,?-1,1?-CH3COO]2·4H2O ?1? The compound was characterized by IR, XRPD, and TGA. |
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