高等学校化学学报

高等学校化学学报 ›› 2013, Vol. 34 ›› Issue (5): 1208.doi: 10.7503/cjcu20120879

• 物理化学 • 上一篇    下一篇

吡啶-2,6-二甲酸氢锂的合成、结构及热化学性质

高振飞, 邸明哲, 邸友莹   

  1. 山东省化学储能与新型电池技术重点实验室, 聊城大学化学化工学院, 聊城 252059
  • 收稿日期:2012-09-24 出版日期:2013-05-10 发布日期:2013-05-10
  • 通讯作者: 邸友莹, 男, 博士, 教授, 主要从事热化学和物理无机化学研究. E-mail: diyouying@126com; diyouying@lcu.edu.cn E-mail:diyouying@126com;diyouying@lcu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 20673050, 20973089, 21273100)资助.

Synthesis, Structure and Thermochemistry of Pyridine-2,6-dicarboxylic Acid Lithium Hydrogen

GAO Zhen-Fei, DI Ming-Zhe, DI You-Ying   

  1. Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, China
  • Received:2012-09-24 Online:2013-05-10 Published:2013-05-10
  • Contact: You-Ying Di E-mail:diyouying@126com;diyouying@lcu.edu.cn

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摘要：

以甲醇和水的混合溶液为溶剂, 合成了吡啶-2,6-二甲酸氢锂Li(HDPC)(H2O)(s), 利用X射线单晶衍射法表征了其晶体结构. 用精密自动绝热热量计测量了其在78～378 K温区的低温热容. 通过最小二乘法拟合得到摩尔热容随折合温度变化的多项式方程, 利用此方程计算出了化合物的舒平热容和各种热力学函数. 设计合理的热化学循环, 利用等温环境溶解-反应热量计分别测定所设计热化学反应的反应物和产物在选定溶剂中的溶解焓, 通过计算得到反应焓为-(46.83 ±0.16) kJ/mol. 利用Hess定律计算出吡啶-2,6-二甲酸氢锂的标准摩尔生成焓为-(747.90 ±1.46) kJ/mol. 利用紫外-可见光谱仪对反应物和产物溶液的测量证实所设计热化学循环的可靠性.

关键词: 吡啶-2,6-二甲酸氢锂, 晶体结构, 低温热容, 标准摩尔生成焓, 热化学循环

Abstract:

Pyridine-2,6-dicarboxylic acid lithium hydrogen [Li(HDPC)(H2O)] was synthesized in methanol and water mixed solvent. X-ray crystallography was applied to characterize its crystal structure. A polynomial equation of experimental molar heat capacities as a function of the temperature was obtained. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated based on the fitted polynomial equation. A reasonable thermochemical cycle was designed on the basis of the preparation reaction of the substance, and the standard molar enthalpies of dissolution for the reactants and products of the hydrothermal reaction in the selected solvent were measured by an isoperibol solution-reaction calorimeter, respectively. The reaction enthalpy was determined to be -(46.83±0.16) kJ/mol. Eventually, the standard molar enthalpy of formation of the title complex was derived to be -(747.90±1.46) kJ/mol by the Hess thermochemical cycle. In addition, the reliability of the designed thermochemical cycle was verified by UV-Vis spectroscopy and refractive indexes.

Key words: Pyridine-2,6-dicarboxylic acid lithium hydrogen, Crystal structure, Low-temperature heat capacity, Standard molar enthalpy of formation, Thermochemical cycle

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