Ahn Hyun Sun, Lee Dong Woo, Ok Kang Min
Department of Chemistry, Chung-Ang University, Seoul, 156-756, Republic of Korea.
Dalton Trans. 2014 Jul 21;43(27):10456-61. doi: 10.1039/c4dt00008k. Epub 2014 Mar 13.
Two new quaternary zirconium iodates, BaZr(IO3)6 and K2Zr(IO3)6, have been synthesized through hydrothermal reactions using BaCO3 (or K2CO3), ZrO2, and HIO3 as reagents. Single crystal and powder X-ray diffraction were used to determine crystal structures of the compounds. BaZr(IO3)6 exhibits infinite bands that are composed of ZrO7 pentagonal bipyramids and IO3 trigonal pyramids, in which Ba(2+) cations are sandwiched by the bands. K2Zr(IO3)6 exhibits a molecular structure that is composed of ZrO6 octahedra and IO3 groups. The dimensionality variations seem to be attributable to the flexible coordination numbers of Zr(4+) cations with large ionic radii as well as the number of counter cations. Both of the materials are thermally stable up to approximately 440-450 °C and decompose to the corresponding metal zirconium oxides above these temperatures. The band gaps for BaZr(IO3)6 and K2Zr(IO3)6 are calculated to be 3.1 and 3.0 eV, respectively, using the (K/S)-versus-E plots obtained from the UV-vis diffuse reflectance spectra. Infrared spectra and local dipole moment calculations are also presented.
通过使用碳酸钡（或碳酸钾）、二氧化锆和碘酸作为试剂进行水热反应，合成了两种新的四元碘酸锆，即BaZr(IO₃)₆和K₂Zr(IO₃)₆。利用单晶和粉末X射线衍射确定了这些化合物的晶体结构。BaZr(IO₃)₆呈现出由ZrO₇五角双锥体和IO₃三角锥体组成的无限带，其中Ba(2+)阳离子夹在这些带之间。K₂Zr(IO₃)₆呈现出由ZrO₆八面体和IO₃基团组成的分子结构。维度变化似乎归因于具有大离子半径的Zr(4+)阳离子的灵活配位数以及抗衡阳离子的数量。这两种材料在高达约440 - 450°C时都具有热稳定性，在这些温度以上分解为相应的金属锆氧化物。利用从紫外可见漫反射光谱获得的(K/S)对E曲线，计算出BaZr(IO₃)₆和K₂Zr(IO₃)₆的带隙分别为3.1和3.0 eV。还给出了红外光谱和局部偶极矩计算结果。
