丙氨酸离子液体[C4mim][Ala]的热化学性质

在298.15 K下利用恒温环境溶解热量计测定了一系列含有已知微量水的1-丁基-3-甲基咪唑丙氨酸盐(C₄mim]Ala])离子液体(IL)不同浓度样品的摩尔溶解焓. 借助Debye-Hückel极限项, 用外推法确定了不同含水量的C₄mim]Ala]样品的标准摩尔溶解焓Δ_sH_m⁰(wc)]. 随着样品中水含量的增加, Δ_sH_m⁰(wc)的绝对值下降, 将Δ_sH_m⁰(wc)对含水量作图得到很好的直线, 其截距Δ_sH_m⁰(pure IL)=-60.74 kJ/mol, 可看作是不含水的C₄mim]Ala]标准摩尔溶解焓的估算值. 利用精密氧弹热量计测定了C₄mim]Ala]的燃烧热, 计算得到其标准摩尔生成焓Δ_fH_m⁰=(-675±11) kJ/mol.

Studies on the Thermo-Chemical Properties of Ionic Liquid Based on Alanine[C_4mim][Ala]

The enthalpies of solution of the ionic liquid(IL) based on alanine 1-butyl-3-methylimidazoliam alanine(C₄mim]Ala]), with various amount of water, Δ_solH_m(wc) was measured over a molality range of about 0.01-0.06 mol/kg by the solution-reaction isoperibol calorimeter at 298.15 K. According to Archer′s method, the standard molar enthalpies of solution of C₄mim]Ala] with a known amounts of water, Δ_solH_m⁰(wc) were obtained. Plotting Δ_solH_m⁰(wc) against water content(w₂), was carried out, a good straight line was obtained and the intercept was the standard molar enthalpy of solution of C₄mim]Ala] without water, Δ_sH_m⁰(pure IL)=Δ_sH_m⁰(pure IL)=-60.74 kJ/mol. Using an oxygen-bomb combustion calorimeter, the molar combustion enthalpy of C₄mim]Ala] was determined at 298.15 K and the standard molar formation enthalpy of C₄mim]Ala], Δ_fH_m⁰=(-675±11) kJ/mol, was obtained.