高等学校化学学报 ›› 2015, Vol. 36 ›› Issue (9): 1759.doi: 10.7503/cjcu20150187

• 物理化学 • 上一篇    下一篇

CsBr-TmBr3-H2O和CsBr-TmBr3-HBr(~13%)-H2O(298.15 K)的相平衡及新固相化合物的热力学和荧光性质

李赵婉, 乔占平(), 陈欣, 党元林, 杨奇超   

  1. 南阳师范学院化学与制药工程学院, 南阳 473061
  • 收稿日期:2015-03-11 出版日期:2015-09-10 发布日期:2015-08-21
  • 作者简介:联系人简介: 乔占平, 男, 教授, 主要从事相平衡和化学热力学方面的研究. E-mail:nyqiaozp@163.com
  • 基金资助:
    国家自然科学基金(批准号: 21173123)资助

Equilibria for the CsBr-TmBr3-H2O and CsBr-TmBr3-HBr(~13%)-H2O Systems at 298.15 K and Thermodynamic and Fluorescent Properties of New Solid-phase Compound

LI Zhaowan, QIAO Zhanping*(), CHEN Xin, DANG Yuanlin, YANG Qichao   

  1. College of Chemistry and Pharmacy Engineering, Nanyang Normal University,Nanyang 473061, China
  • Received:2015-03-11 Online:2015-09-10 Published:2015-08-21
  • Contact: QIAO Zhanping E-mail:nyqiaozp@163.com
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21173123)

摘要:

采用等温溶度法测量了三元体系CsBr-TmBr3-H2O和四元体系CsBr-TmBr3-HBr(~13%)-H2O在298.15 K时的相平衡溶度数据, 并绘制了相应的相图. 三元体系和四元体系均由3个平衡固相CsBr, Cs3Tm2Br9·16H2O和TmBr3·8H2O构成. 新固相化合物Cs3Tm2Br9·16H2O在三元和四元体系均是固液异成分溶解的化合物, 且其结晶区随平衡液相中氢溴酸浓度的增加而增大. 用X射线粉末衍射仪(XRD)、 热重分析仪和荧光光谱仪对Cs3Tm2Br9·16H2O进行了表征. 结果表明, 当用712 nm光激发时, Cs3Tm2Br9·16H2O在471 nm处具有上转换发光性能. 用微量热仪测定了Cs3Tm2Br9·16H2O在无限稀释下的标准摩尔溶解焓为-(11.63±0.46) kJ/mol, 确定其标准摩尔生成焓为-(7826.2±1.2) kJ/mol.

关键词: 相平衡, 溴化铯, 溴化铥, 标准摩尔生成焓, 荧光性质

Abstract:

The phase equilibria of the ternary system CsBr-TmBr3-H2O and the quaternary system CsBr-TmBr3-HBr(~13%)-H2O at 298.15 K were investigated by the isothermal solubility method. Based on the experimental data, the corresponding phase diagrams were plotted. In the ternary system, three crystallization regions corresponding to CsBr, Cs3Tm2Br9·16H2O and TmBr3·8H2O were found. Similarly, there were three crystallization regions corresponding to CsBr, Cs3Tm2Br9·16H2O and TmBr3·8H2O in the quaternary system. The phase diagrams of the ternary and quaternary systems were compared and a new double salt Cs3Tm2Br9·16H2O is formed which is incongruently soluble in the two systems; the area of the crystallization region of Cs3Tm2Br9·16H2O increases with the increasing concentration of HBr in the equilibrium liquid phase. The new solid-phase compound Cs3Tm2Br9·16H2O was characterized by chemical analysis, X-ray diffraction(XRD) and thermal gravity-differential thermal gravity(TG-DTG) techniques. The fluorescence excitation and emission spectra of Cs3Tm2Br9·16H2O were measured. Upconversion emission of the new solid phase was found at 471 nm when excited at 712 nm. The standard molar enthalpy of solution of Cs3Tm2Br9·16H2O in water was measured to be -(11.63±0.46) kJ/mol by microcalorimetry under the condition of infinite dilution and its standard molar enthalpy of formation was determined as -(7826.2±1.2) kJ/mol.

Key words: Phase diagram, Cesium bromide, Thulium bromide, Standard molar enthalpy of formation, Fluorescent property

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