Controlled Assembly of a Dawson-like Antimoniotungstate-Supported Trefoil-type Trimer with Good Proton Conductivity...

With the excellent properties of POM in the field of proton conductivity, the preparation of POM-based proton-conductive materials has burst into life. Herein, an unprecedented Sb-templated all-inorganic trimer Na₈H_18.64[(SbW₁₄O₅₂)₃(Sb₂W_6.12Ru_5.88O₁₈)]·85H₂O (1), which is based on tetravacant Dawson-like [SbW₁₄O₅₂]^17- blocks and exhibits a trefoil type with D₃ symmetry, has been successfully designed and synthesized by the assembly of simple materials with a one-pot hydrothermal method under acidic conditions. Also, compound 1 is systematically characterized by single-crystal X-ray diffraction, PXRD, ESI-MS, IR spectroscopy, UV-vis, elemental analysis, and TGA. Crystal structure data analysis demonstrates that compound 1 is constructed by a hexagonal prismatic heterometallic {Sb₂W_6.12Ru_5.88O₁₈} core and three equivalent {SbW₁₄} units bridged through μ₂-O atoms in periphery. Subsequently, further property experiments show that compound 1 exhibits high proton conductivity with a conductivity value (σ) of 3.07 × 10^-2 S cm^-1 at 75 °C and 80% relative humidity (RH). The activation energy of compound 1 evaluated by the Arrhenius plots is 0.22 eV, which indicates that the Grotthuss mechanism is dominant during the process of proton transfer.