Chen Kaizhou, Wang Yongtao, Yao Jia, Li Haoran
Department of Chemistry, ZJU-NHU United R&D Center and ‡State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, P. R. China.
J Phys Chem B. 2018 Jan 11;122(1):309-315. doi: 10.1021/acs.jpcb.7b10671. Epub 2017 Dec 26.
The degree of proton transfer and thermodynamic parameters of six acetate-based protic ionic liquids (PILs) were measured using nuclear magnetic resonance spectroscopy and calculated by van't Hoff analytical method, respectively. The degree of proton transfer of these PILs at 298 K spread over a large range, which is from 39.6% (1-methylpyrrolidinium acetate, [MpyrH][AcO]) to 94.4% (1-butylimidazolium acetate, [BuimH][AcO]). The calculated standard enthalpy change of the reaction (ΔH) is from -23.30 to -7.80 kJ mol and the standard entropy change of the reaction (ΔS) is from -42.70 to -8.07 J mol K. The correlation between the degree of proton transfer and aqueous ΔpK or ΔH was investigated as well. Furthermore, in some special cases, ΔS, especially the entropy change of symmetry, also plays an important role in affecting the degree of proton transfer.
使用核磁共振光谱法测量了六种醋酸盐类质子离子液体（PILs）的质子转移程度和热力学参数，并分别通过范特霍夫分析法进行了计算。这些PILs在298 K时的质子转移程度分布范围很广，从39.6%（1-甲基吡咯烷鎓醋酸盐，[MpyrH][AcO]）到94.4%（1-丁基咪唑鎓醋酸盐，[BuimH][AcO]）。计算得到的反应标准焓变（ΔH）为-23.30至-7.80 kJ/mol，反应标准熵变（ΔS）为-42.70至-8.07 J/(mol·K)。还研究了质子转移程度与水相ΔpK或ΔH之间的相关性。此外，在某些特殊情况下，ΔS，尤其是对称熵变，在影响质子转移程度方面也起着重要作用。
