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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (01): 46-52. 上一篇    下一篇

研究论文

三氧化二硼和五硼酸钠水合物非晶结构

周永全1，房艳1，曹领帝1,2，朱发岩1,2，房春晖*,1   

  1. (1中国科学院青海盐湖研究所中国科学院盐湖资源与化学重点实验室 西宁 810008)
    (2中国科学院研究生院 北京 100049)
  • 投稿日期:2010-06-24 修回日期:2010-07-24 发布日期:2010-08-30
  • 通讯作者: 周永全 E-mail:yongqzhou@163.com
  • 基金资助:

    国家重点基础研究发展计划前期专项;国家自然科学基金资助项目.

Amorphous Structure of Diboron Trioxide and Sodium Pentaborate Hydrate

Zhou Yongquan1 Fang Yan1 Cao Lingdi1,2 Zhu Fayan1,2 Fang Chunhui*,1   

  1. (1 CAS Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008)
    (2 Graduate School of Chinese Academy of Sciences, Beijing 100049)
  • Received:2010-06-24 Revised:2010-07-24 Published:2010-08-30
  • Contact: Zhou YongQuan E-mail:yongqzhou@163.com

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被引次数

11

X射线衍射法测量了三氧化二硼及五硼酸钠水合物的非晶结构, 通过非晶衍射实验数据处理, 得到了它们的径向分布函数(RDF). 模型定量计算, 得到了其短程有序结构, 三氧化二硼水合物非晶中75%的硼参与形成平面硼氧六元环(boroxol), 给出了环内ortho-B—O, meta-O—O, meta-B—B和para-B—O相互作用的距离和作用数, 支链与硼氧六元环之间的夹角为125°±15°; 五硼酸钠水合物非晶中, 由两个硼氧三角形(B△)和一个硼氧四面体(B□)构成的两个变形六元环通过公共顶点(B□)相连而形成五硼酸阴离子, 高度有序的离子内相互作用占绝对优势. 六配位Na＋与五硼酸阴离子中一端氧相连, Na—B特征距离为0.330 nm.

关键词: 非晶, X射线衍射, 三氧化二硼水合物, 五硼酸钠水合物, 短程有序结构, 径向分布函数(RDF)

We determined the structures of amorphous diboron trioxide and sodium pentaborate hydrate by X-ray diffractometry. Radial distribution functions (RDF) of those samples were obtained from precisely diffraction data processing. Their short-range ordered structures were determined by model design and quantitative calculations. In amorphous diboron trioxide hydrate, 75% of boron atoms construct planar six-membered boroxol ring and the interatomic distance and the interactions numbers of intra-ring ortho-B—O, meta-O—O, meta-B—B and para-B—O were listed out, where boron-oxygen branched-chain intersects with the plane at a terminal-oxygen with a intersect angle of 125°±15°. The basic structure unit of non-crystalline sodium pentaborate hydrate is formed by two planar six-membered boroxol rings deformed, composed of two boron-oxygen triangles (B△) and a boron-oxygen tetrahedron (B□), through the shared B□. The highly ordered intra-anion interactions are the upmost interactions. Six coordinated Na＋ connects with the terminal-oxygen of pentaborate to form a contact ion pair with a characteristic distance (B—Na) of 0.330 nm.

Key words: amorphous, X-ray diffraction, diboron trioxide hydrate, sodium pentaborate hydrate, short-range ordered structure, radial distribution function (RDF)