Ba3[Ge2B7O16(OH)2](OH)(H2O) and Ba3Ge2B6O16: novel alkaline-earth borogermanates based on two types of polymeric borate units and GeO4 tetrahedra.
Ba3[Ge2B7O16(OH)2](OH)(H2O) and Ba3Ge2B6O16: novel alkaline-earth borogermanates based on two types of polymeric borate units and GeO4 tetrahedra.
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DOI：
10.1021/ic1025697
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发表时间：
2011-03
影响因子：
4.6
通讯作者：
Jian-Han Zhang;F. Kong;J. Mao
中科院分区：
文献类型：
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作者：
Jian-Han Zhang;F. Kong;J. Mao
通过水热或高温固相反应合成了两种具有两种新颖结构的新型硼锗酸钡，即Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O)和Ba(3)Ge(2)B(6)O(16)。它们代表了碱土金属硼锗酸盐的第一个例子。 Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O)在极性空间群Cc中结晶。其结构具有新颖的三维阴离子骨架，由[B(7)O(16)(OH)(2)](13-)聚阴离子组成，由Ge原子桥接，沿b轴具有一维(1D) 10元环(MR)隧道。 Ba(II) 阳离子、氢氧根离子和水分子位于上述隧道中。 Ba(3)Ge(2)B(6)O(16)在中心对称空间群P1中结晶。其结构呈现出由圆形B(6)O(16)单元组成的厚层，通过GeO(4)四面体通过共享角连接，沿c轴形成一维4-和6-MR隧道。 Ba1 离子驻留在 6-MR 的隧道中，而 Ba2 离子则位于层间空间。这两种化合物都具有新型拓扑结构。二次谐波产生 (SHG) 测量表明 Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) 显示出较弱的 SHG 响应，约为 KH(2)PO(4) 的 0.3 倍。还进行了光学、热稳定性和铁电特性以及理论计算。
Two new barium borogermanates with two types of novel structures, namely, Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) and Ba(3)Ge(2)B(6)O(16), have been synthesized by hydrothermal or high-temperature solid-state reactions. They represent the first examples of alkaline-earth borogermanates. Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) crystallized in a polar space group Cc. Its structure features a novel three-dimensional anionic framework composed of [B(7)O(16)(OH)(2)](13-) polyanions that are bridged by Ge atoms with one-dimensional (1D) 10-membered-ring (MR) tunnels along the b axis. The Ba(II) cations, hydroxide ions, and water molecules are located at the above tunnels. Ba(3)Ge(2)B(6)O(16) crystallizes in centrosymmetric space group P1. Its structure exhibits a thick layer composed of circular B(6)O(16) units connected by GeO(4) tetrahedra via corner sharing, forming 1D 4- and 6-MR tunnels along the c axis. Ba1 ions reside in the tunnels of the 6-MRs, whereas Ba2 ions are located at the interlayer space. Both compounds feature new types of topological structures. Second-harmonic-generation (SHG) measurements indicate that Ba(3)[Ge(2)B(7)O(16)(OH)(2)](OH)(H(2)O) displays a weak SHG response of about 0.3 times that of KH(2)PO(4). Optical, thermal stability, and ferroelectric properties as well as theoretical calculations have also been performed.