吡啶-2,6-二甲酸氢锂的合成、结构及热化学性质  

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

作　　者：高振飞[1] 邸明哲[1,2] 邸友莹[1] 

机构地区：[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 [2]陕西省三原县妇幼保健院

出　　处：《高等学校化学学报》2013年第5期1208-1213,共6页Chemical Journal of Chinese Universities

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

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.Pyridine-2,6-dicarboxylic acid lithium hydrogen and water mixed solvent. X-ray crystallography was applied [ Li （HDPC） （ H2 O） ] was synthesized in methanol 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 polyno- mial 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） k J/tool by the Hess thermochemical cycle. In addition, the reliability of the designed thermochemical cycle was verified by UV-Vis spectroscopy and re- fractive indexes.

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 

分 类 号：O642.3[理学—物理化学]