物理化学学报 >> 2015, Vol. 31 >> Issue (11): 2036-2042.doi: 10.3866/PKU.WHXB201509111

热力学,动力学和结构化学 上一篇    下一篇

1-乙基-3-甲基咪唑丙氨酸离子液体热力学性质的研究

郑玲1,樊本汉1,卜晓雪1,潘懿1,董家新2,关伟1,*()   

  1. 1 辽宁大学化学院,沈阳110036
    2 广西师范大学化学化工学院,广西桂林541004
  • 收稿日期:2015-07-30 发布日期:2015-11-13
  • 通讯作者: 关伟 E-mail:guanweiy@sina.com
  • 基金资助:
    国家自然科学基金(21173107);辽宁省高等学校优秀人才支持计划(2015025)

Study on Thermodynamic Properties of Ionic Liquid 1-Ethyl-3-methylimidazolium Alanine

Ling. ZHENG1,Ben-Han. FAN1,Xiao-Xue. BU1,Yi. PAN1,Jia-Xin. DONG2,Wei. GUAN1,*()   

  1. 1 College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
    2 College of Chemistry & Chemical Engineering, Guangxi Normal University, Guilin 541004, Guangxi Province, P. R. China
  • Received:2015-07-30 Published:2015-11-13
  • Contact: Wei. GUAN E-mail:guanweiy@sina.com
  • Supported by:
    the National Natural Science Foundation of China(21173107);Liaoning Excellent Talents in University, China(2015025)

摘要:

用中和法合成了氨基酸离子液体1-乙基-3-甲基咪唑丙氨酸([C2mim][Ala]),并利用恒温环境的溶解反应热量计,在(288.15±0.01) K-(308.15±0.01) K温度范围内每隔5 K,测定不同质量摩尔浓度离子液体在水中的溶解焓(ΔsolHmθ).根据Archer的方法,通过线性拟合得到了该离子液体的标准摩尔溶解焓(Δsol),并计算了其相对表观摩尔溶解焓(ΦL).在298.15 K下,根据Glasser经验方法得到了格子能UPOT = 566 kJ·mol-1,并计算了其阴阳离子水化焓值(ΔH+ + ΔH-) = -620 kJ·mol-1及阴离子水化焓ΔH-([Ala]-) = -387 kJ·mol-1.此外,估算了[C2mim][Ala]水溶液的热容(Cp(sol))和表观摩尔热容(ΦCp).

关键词: 离子液体, 溶解焓, 热容, 水化焓, 格子能

Abstract:

We synthesized the alanine-based ionic liquid [C2mim][Ala] (1-ethyl-3-methylimidazolium alanine) by using the neutralization method and characterized it. Using a solution-reaction isoperibol calorimeter, we determined the molar enthalpies of the solution (ΔsolHm) at various molalities in water from (288.15±0.01) to (308.15±0.01) K in intervals of 5 K. Using Archer's method, we obtained the standard molar enthalpy of solution for [C2mim][Ala] (ΔsolHmθ) and calculated its apparent relative molar enthalpy (ΦL). Using Glasser's theory of lattice energy, we obtained the lattice energy, UPOT = 566 kJ·mol-1, the hydration enthalpy of the cation and anion, (ΔH+ + ΔH-) = -620 kJ·mol-1, and the hydration enthalpy of an anion, ΔH-([Ala]-) = -387 kJ·mol-1 at 298.15 K. Finally, we obtained the heat capacity of aqueous [C2mim][Ala] (Cp(sol)) and its apparent molar heat capacity (ΦCp) at various specific molalities.

Key words: Ionic liquid, Enthalpy of solution, Heat capacity, Hydration enthalpy, Lattice energy