新型水合稀土多硼酸盐Ln[B_5O_8(OH)_2](Ln=Pr,Nd)的合成与结构  

Synthesis and Structure of a Novel Hydrated RareEarth Polyborate, Ln[B_5O_8(OH)_2](Ln=Pr,Nd)

作　　者：李林艳[1] 廖复辉[1] 李国宝[1] 林建华[1] 

机构地区：[1]北京大学稀土材料化学与应用国家重点实验室化学与分子工程学院

出　　处：《无机化学学报》2005年第7期949-954,共6页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金资助项目(No.20471003)。

摘　　要：采用熔融硼酸法在200℃下合成了一种具有层状结构的新型水合稀土多硼酸盐,Ln[B5O8(OH)2](Ln=Pr,Nd),并利用粉末X射线衍射技术确定了它的结构。Ln[B5O8(OH)2]晶体属于单斜晶系、P21/c空间群,它的基本构建单元(FBB)是由3个BO4和2个BO3组成的双三元环,[B5O12](2Δ+3T)。每一个FBB和邻近的4个FBB通过共用氧原子相连,形成了具有九元环窗口的层状硼酸根基团,稀土离子位于九元环中心附近。CSD:391317。A novel hydrated rare earth polyborate, Ln[B5O8(OH)(2)] (Ln=Pr, Nd) has been synthesized by using boric acid as a flux at 200 degrees C. Its crystal structure is established by powder X-ray diffraction technique. Ln[B5O8(OH)(2)] crystallizes in monoclinic space groupP2(1)/c. The title compounds consist of a double three-membered ring composed of three BO4 and two BO3 groups as the fundamental building block. The FBB shares four common oxygen atoms with the adjacent FBBs, producing a borate layer containing nine-membered borate ring window, of which the rare earth cations are located around the center. The Ln(3+) cations are coordinated with ten oxygen atoms from the nine-membered ring window and the adjacent borate layer. The borate layers are stacked along the b axis and are interlinked by the Ln-O bond.

关 键 词：多硼酸盐 水合 合成 粉末X射线衍射技术 层状结构 单斜晶系 稀土离子 FBB 空间群 P21 三元环 氧原子 硼酸根 CSD 晶体 基团 

分 类 号：O614.111[理学—无机化学] TM923.04[理学—化学]