Liu Jian-Cai, Han Qing, Chen Li-Juan, Zhao Jun-Wei, Streb Carsten, Song Yu-Fei
Henan Key Laboratory of Polyoxometalate Chemistry, Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan, 475004, China.
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Angew Chem Int Ed Engl. 2018 Jul 9;57(28):8416-8420. doi: 10.1002/anie.201803649. Epub 2018 May 14.
The exploration of high nuclearity molecular metal oxide clusters and their reactivity is a challenge for chemistry and materials science. Herein, we report an unprecedented giant molecular cerium-bismuth tungstate superstructure formed by self-assembly from simple metal oxide precursors in aqueous solution. The compound, {[W Ce O ]([W Bi Ce (H O) O ][B-α-BiW O ] ) } was identified by single-crystal X-ray diffraction and features 104 metal centers, a relative molar mass of ca. 24 000 and is ca. 3.0×2.0×1.7 nm in size. The cluster anion is assembled around a central {Ce } octahedron which is stabilized by several molecular metal oxide shells. Six trilacunary Keggin anions ([B-α-BiW O ] ) cap the superstructure and limit its growth. In the crystal lattice, water-filled channels with diameters of ca. 0.5 nm are observed, and electrochemical impedance spectroscopy shows pronounced proton conductivity even at low temperature.
对高核分子金属氧化物簇及其反应活性的探索是化学和材料科学面临的一项挑战。在此，我们报道了一种前所未有的巨型分子铈铋钨酸盐超结构，它是由简单的金属氧化物前驱体在水溶液中自组装形成的。通过单晶X射线衍射鉴定出该化合物{W₁₈Ce₈O₆₂}，其具有104个金属中心，相对摩尔质量约为24000，尺寸约为3.0×2.0×1.7 nm。簇阴离子围绕着一个中心{Ce₈}八面体组装，该八面体由几个分子金属氧化物壳层稳定。六个三缺位Keggin阴离子([B-α-BiW₉O₃₃]⁶⁻)覆盖超结构并限制其生长。在晶格中，观察到直径约为0.5 nm的充满水的通道，并且电化学阻抗谱显示即使在低温下也具有显著的质子传导性。
