SrGe2B2O8 and Sr3Ge2B6O16: Novel Strontium Borogermanates with Three-Dimensional and Layered Anionic Architectures
SrGe2B2O8 and Sr3Ge2B6O16: Novel Strontium Borogermanates with Three-Dimensional and Layered Anionic Architectures
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SrGe2B2O8 和 Sr3Ge2B6O16：具有三维层状阴离子结构的新型硼锗酸锶
DOI：
10.1021/ic402214p
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发表时间：
2013-12-02
影响因子：
4.6
通讯作者：
Mao, Jiang-Gao
中科院分区：
文献类型：
--
作者：
Hao, Yu-Cheng;Hu, Chun-Li;Mao, Jiang-Gao
采用高温固相反应法合成了两种新的碱土金属锶硼锗酸盐SrGe 2B 2 O 8和Sr 3Ge 2B 6 O 16。它们代表了硼锗酸锶的第一个例子。SrGe 2B 2 O 8晶体属Pnma空间群，其结构特征是由B2 O 7和Ge 2 O 7二聚体单元交替连接构成的新型三维[Ge 2B 2 O 8]（2-）骨架，沿B轴沿着由Sr 2+阳离子填充的八元环（MR）的一维（1D）隧道。Sr_3Ge_2B_6O_（16）与Ba_3Ge_2B_6O_（16）是同构的，晶体中心对称，空间群为P（1）。它的结构特征是由圆形B6 O 16簇和GeO 4四面体组成的二维层，它们通过角共享相互连接，形成沿沿着轴的ID四和六MR隧道。Sr（1）阳离子位于六磁共振隧道中，而Sr（2）阳离子位于层间空间中。研究了它们的光学性质、热稳定性以及基于密度泛函理论的能带结构。
Two new alkaline-earth strontium borogermanates, namely, SrGe2B2O8 and Sr3Ge2B6O16, have been successfully synthesized through high-temperature solid state reactions. They represent the first examples of strontium borogermanates. SrGe2B2O8 crystallized in space group Pnma, and its structure features a novel three-dimensional [Ge2B2O8](2-) framework composed of alternative linkages of the B2O7 and Ge2O7 dimeric units with one-dimensional (1D) tunnels of eight-membered rings (MRs) along the b axis that are filled by the Sr2+ cations. Sr3Ge2B6O16 is isostructural with Ba3Ge2B6O16 and crystallizes in centrosymmetric space group P (1) over bar. Its structure features a two-dimensional layer that is composed of circular B6O16 clusters and GeO4 tetrahedra that are interconnected via corner sharing, forming ID four- and six-MR tunnels along a axis. Sr(1) cations are located in the six-MR tunnels, whereas Sr(2) cations are located in the interlayer space. Studies of their optical properties and thermal stability as well as band structure calculations based on density functional theory methods have been also performed.