Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (11): 2036-2042.doi: 10.3866/PKU.WHXB201509111

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

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)

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

MSC2000: 

  • O642