A study on proton conduction in a layered metal-organic framework, Rb-2(adp)[Zn-2(ox)(3)]center dot 3H(2)O (adp = adipic acid, ox(2-) = oxalate)

作者：Sadakiyo Masaaki^*; Yamada Teppei; Kitagawa Hiroshi^*

来源：Inorganic Chemistry Communications, 2016, 72: 138-140.

DOI：10.1016/j.inoche.2016.08.016

• Proton conduction
• Metal-organic framework

We newly synthesized a metal-organic framework (MOP) Rb-2(adp)[Zn-2(ox)(3)]center dot 3H(2)O (adp = adipic acid; ox(2-) = oxalate), where the rubidium ions, carboxylic acid groups, and water molecules are located in an interlayer space of a two-dimensional (2-D) oxalate-bridged network. The structure of this compound was determined using single-crystal X-ray diffraction analysis. Hydrated phases of this compound were examined using thermograviinetry and water vapor adsorption measurements. Proton conductivity in this MOF was investigated by alternating current impedance measurements. Systematic comparison with previously reported isomorphous 2-D compounds A(2)(adp)[Zn-2(ox)(3)]center dot 3H(2)O (A = NH4 and K) showed that the difference in the ionic radii of the cations leads to a difference in activation energy of proton conductivity and that absence of NH4 ions causes a significant decrease in proton conductivity, even though the ionic radius of Rb+ (1.52 angstrom) is closer to that of NH4+ (1.61 angstrom) than that of K+ (1.38 angstrom).

• 出版日期2016-10